Synthesis of heterocyclic N-(beta-d-glucopyranosyl)carboxamides for inhibition of glycogen phosphorylase

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Graphical abstract pp xxx–xxxSynthesis of heterocyclic N-(bDD -glucopyranosyl)carboxamides for inhibition of glycogen phosphorylase Bálint Kónya, Tibor Docsa, Pál Gergely, László Somsák * O OAc AcO AcO OAc H N O O OH HO HO OH H N O N N N R O OH HO HO OH H N O N O R Key steps: 1,3-dipolar cycloadditions R-N 3 R-C N O Best inhibitors a g ainst rabbit muscle g l y co g en phosphor lase b R = 3,5-(CH 3 ) 2 -C 6 H 3 - K i = 34 µM R = Indol-2-yl K i = 164 µM CAR 6067 No. of Pages 1, Model 5G 8 February 2012 1 Synthesis of heterocyclic N-(b-D-glucopyranosyl)carboxamides for inhibition of glycogen phosphorylase Bálint Kónya a ,Tibor Docsa b ,Pál Gergely b,c ,László Somsák a, ⇑ a Department of Organic Chemistry, University of Debrecen, PO Box 20, H-4010 Debrecen, Hungary b Cell Biology and Signaling Research Group of the Hungarian Academy of Sciences at the Department of Medical Chemistry, Medical and Health Science Centre, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary c Department of Medical Chemistry, Medical and Health Science Centre, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary 10 article info Article history: Received 4 December 2011 Received in revised form 19 January 2012 Accepted 22 January 2012 Available online xxxx Keywords: Azide–alkyne cycloaddition Nitrile-oxide–alkyne cycloaddition 1,2,3-Triazole-4-carboxamide Isoxazole-5-carboxamide N-(bD -Glucopyranosyl)carboxamide Glycogen phosphorylase abstract In a DCC-mediated coupling 2,3,4,6-tetra-O-acetyl-b-D-glucopyranosylamine and propiolic acid gave N-propynoyl-2,3,4,6-tetra-O-acetyl-b-D-glucopyranosylamine which was transformed by 1,3-dipolar cycloadditions with aromatic azides and nitrile-oxides to the corresponding O-peracetylated N-(b-D-glucopyranosyl)-1-substituted-1,2,3-triazole-4-carboxamides and N-(b-D-glucopyranosyl)-3-substitutedisoxazole-5-carboxamides, respectively. These compounds were O-deacetylated by Zemplén’s protocol to be tested as inhibitors of rabbit muscle glycogen phosphorylase b. The best inhibitors of the two series were N-(b-D-glucopyranosyl)-1-(3,5-dimethyl-phenyl)-1,2,3-triazole-4-carboxamide (K i =34 l M) and N-(b-D-glucopyranosyl)-3-(indol-2-yl)-isoxazole-5-carboxamide (K i = 164 l M). Ó2012 Elsevier Ltd. All rights reserved. 1. Introduction Inhibitors of glycogen phosphorylase (GP) enzymes have been 40 considered as possible means for therapeutic intervention in first of all type 2 diabetes but also other diseased states. For the biochemical rationale behind these considerations the reader is kindly referred to recent review articles. 1–6 As part of an ongoing project to synthesize new glucose derivatives 7 for the inhibition of GP Nacyl-bD -glucopyranosylamines 8 (Chart 1,I:e.g. for R = 2-naphthyl K i (against rabbit muscle GPb, RMGPb) 10 l M 8 or 13 l M 9 ) as well as N-acyl-N 0 -bD -glucopyranosyl urea derivatives 4 II (R = 2-naphthyl: K i (RMGPb) 0.35 l M) have been taken as lead structures. Non-classical bioisosteric replacement of the NHCO moiety in I 50 by the heterocyclic linker Arevealed high similarity of the amide (see K i of Iabove) and the 1,2,3-triazole type (for IA R = 2-naphthyl: K i (RMGPb) 16 l M 9 ) inhibitors both in binding strength and structural features of the enzyme–inhibitor complexes. 9,10 Applying the isomeric B,C, and Dmoieties as linkers resulted in inhibitors of varying efficiency, 11,12 whereby the 3-aryl-5-bD - glucopyranosyl-1,2,4-oxadiazole (ID type) derivatives proved to be the most potent compounds (for the best inhibitor where R = 2-naphthyl the K i (RMGPb) was 2.4 l M 12 ). Very recently we have reported on the synthesis and enzymatic evaluation of a 60 series of compounds of type II with linker 1 and linker 2 being 1,2,3-triazoles Aand Fas well as 1,3,4-oxadiazole Bin various coupling patterns. 13 The best inhibitors against RMGPb were effective in the upper micromolar range (linker 1 = A, linker 2 = B, R = Ph: K i 854 l M; linker 1 = B, linker 2 = F, R = 2-naphthyl: K i 745 l M). 0008-6215/$ - see front matter Ó2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.carres.2012.01.020 ⇑ Corresponding author. Tel.: +36 52 512 900x22348; fax: +36 52 512 744. E-mail address: [email protected] (L. Somsák). O HO HO HO OH H NR O lin k er O HO HO HO OH H NH N O O R linker 1 linker 2 O HO HO HO OH H NH N O O R linker lin ers N N N N O N N N O O N N ON I II III A B C D E N N N F Chart 1. Q1 Q2 Carbohydrate Research xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect Carbohydrate Research journal homepage: www.elsevier.com/locate/carres CAR 6067 No. of Pages 9, Model 5G 8 February 2012 Please cite this article in press as: Kónya, B.; et al. Carbohydr. Res. (2012), doi:10.1016/j.carres.2012.01.020 Herein we report on the synthesis and enzymatic test of some compounds of type III with isoxazole Eand 1,2,3-triazole Fas linkers. 2. Results and discussion For the preparation of compounds of type IIIE and IIIF construc70 tion of the heterocyclic parts by 1,3-dipolar cycloadditions 14 of an alkyne and nitrile-oxides 15 as well as azides, 16,17 respectively, was envisaged. As the direct transformation of azide 1 18 by acylation of an in situ generated iminophosphorane 19 with propiolic acid failed, the necessary protected N-propynoyl-bD -glucopyranosylamine 3 was obtained from glucosylamine 2 20 and propiolic acid by a DCC-mediated coupling in high yield (Scheme 1). The copper(I) catalyzed cycloaddition reaction (CuAAC) of 3 with aromatic azides was investigated first (Scheme 2). The noncommercial azides were prepared either in situ from the corre80 sponding boronic acids following a recently published procedure 21 or from the related aniline derivatives via diazonium salts. 22 The widely used system CuSO 4 – L -ascorbic acid was applied to generate the catalyst, and the cycloadducts 4–8 were obtained in high yields. A trial with a recently published catalyst Cu(PPh 3 ) 2 NO 323 in 2 mol % loading under the same conditions did not significantly improve the yield of 4(93%). Alkyne 3was next transformed with nitrile-oxides which were oxidatively generated in situ from aromatic aldoximes by using domestic bleach. 24 The target compounds 14–20 were obtained 90 in modest to acceptable yields, among which the indole derivatives 19 and 20 having an NH group could be isolated in the lowest yields. O-Acetyl protecting groups were removed by the Zemplén protocol to give the test compounds 9–13 and 21–27 (Schemes 2 and 3, respectively) in high yields. Proton and carbon NMR spectra of triazoles 4–13 and isoxazoles 14–27 contained resonances for the sugar part and the amide moiety of the compounds as expected. In the 13 C NMR spectra signals for the triazole C-4 (quaternary) and C-5 (CH) appeared in 100 the 140–143 and 116–121 ppm range, respectively, thereby corroborating the anticipated 1,4-disubstitution pattern of the 1,2,3triazole in analogy with previously reported compounds. 10 The isoxazole C(4)–H appeared in the 7.2–7.3 ppm range for the protected derivatives 14–20, and in the 7.5–7.9 ppm range for the unprotected 21–27. HMBC spectra allowed to identify isoxazole C3 (155–163 ppm) and C5 (162–166 ppm) resonances in the whole series 14–27. Furthermore, detection of crosspeaks between isoxazole C–H and both the amide CO and a quaternary carbon of the aromatic substituent indicated the formation of 3-aryl-isoxazole110 5-carboxamides 14–20 (contrary to the possibility of 3-aryl-isoxazole-4-carboxamide derivatives). The heterocyclic N-(bD -glucopyranosyl) carboxamides were tested for their inhibitory activity against rabbit muscle glycogen phosphorylase b as described earlier, 8 and the obtained data, together with some relevant literature values, are collected in Table 1. The triazole derivatives 9and 11–13 had inhibitor constants in the micromolar range. The inactivity of the 2-naphthyl compound O OAc AcO AcO O Ac N 3 O OAc AcO AcO Ac NH 2 O OAc AcO AcO OAc H N O HC C COOH HC C COOH 2. 1. PMe 3 88 % H 2 /Ra-Ni 12 3 DCC Scheme 1. O OAc AcO AcO OAc H N O 3 ArN 3 CuSO 4 .5 H 2 O (5 mol%) L -ascorbic acid (15 mol%) CH 2 Cl 2 -H 2 O 1:1, 50 °C ArB(OH) 2 NaN 3 CuSO 4 .5 H 2 O (10 mol%) MeOH NaOMe MeOH O OR RO RO OR H N O N N N A r Ar R = Ac R = H Ph 4 (91 %) 9 (88 %) 2-Naphthyl 5 (75 %) 10 (61 %) 3,5-di-Me-C 6 H 3 6 (78%) 11 (87 %) 4-CF 3 -C 6 H 4 7 (79 %) 12 (70 %) 4t Bu-C 6 H 4 8 (85 %) 13 (79 %) 4-89-13 ArNH 2 + towards 5 and 6 towards 7 and 8 1. NaNO 2 , HCl, 0 o C 2. NaN 3 rt Scheme 2. O OAc AcO AcO Ac H N O O OR RO RO OR H N O N O Ar ArCH=NOH, NaOCl, THF-H 2 O Ar R = Ac R = H Ph 14 (55 %) 21 (97 %) 2-Naphthyl 15 (52 %) 22 (91 %) Benzo-[b]-furan-2-yl 16 (50 %) 23 (88 %) Benzo-[b]-thiophen-2-yl 17 (51 %) 24 (95 %) Benzothiazol-2-yl 18 (30 %) 25 (90 %) Indol-2-yl 19 (24 %) 26 (76 %) Indol-3-yl 20 (20 %) 27 (70 %) 3 NaOMe MeOH 14-20 21-27 Scheme 3. 2B. Kónya et al. / Carbohydrate Research xxx (2012) xxx–xxx CAR 6067 No. of Pages 9, Model 5G 8 February 2012 Please cite this article in press as: Kónya, B.; et al. Carbohydr. Res. (2012), doi:10.1016/j.carres.2012.01.020 10 was surprising especially in the light of very strong inhibition by 2-naphthyl derivatives in other series of glucose based inhibi120 tors, 7 for example, acyl ureas 28–32 from which 29 had the highest affinity. While in these latter cases the inhibition became stronger with increasing size of the aromatic part of the molecules, this tendency seemed to be reversed among triazoles 9–13. The relatively weak binding of a more or less similar triazole derivative 33 was attributed to the diminished number of interactions of the inhibitor with the protein as well as to the steric bulk of the aglycone inducing unfavorable changes in the vicinity of the binding site (more specifically the so-called 280s loop next to the catalytic center). 25 The present observations might have a similar origin. 130 In addition, the bioisosteric relationship of the amide and the 1,2,3-triazole moieties, which proved to be valid for N-acyl-bD - glucopyranosylamines and 1-bD -glucopyranosyl-4-substituted1,2,3-triazoles 9 outlined in the introduction, cannot be justified for the case of the ‘second’ NHCO group of the N-acyl-N 0 -bD -glucopyranosyl urea type GP inhibitors. Inhibition of RMGPb by the isoxazoles 21–27 was even weaker. Thus, phenyl-isoxazole 21 had a more than twice less affinity than its triazole counterpart 9. An increase in the size of the aromatic moiety as in compounds 22–25 resulted in a complete loss of activ140 ity. Interestingly, the indole derivatives 26 and 27, in which the steric bulk of the rings must be essentially the same as in 23–25, showed weak binding similar to that of 21. This might be due to the hydrogen bond donor capacity of this ring system. It can also be envisaged that these compounds bind to the so-called new allosteric (or indole binding) site of the enzyme where some glucose derivatives were also shown to be accommodated. 4,26,27 These points need further investigations. In summary, 1,3-dipolar cycloadditions of aromatic azides and nitrile-oxides were used as the key steps in the synthesis of N150 (bD -glucopyranosyl)-1-substituted-1,2,3-triazole-4-carboxamides and N-(bD -glucopyranosyl)-3-substituted-isoxazole-5-carboxamides, respectively. The new compounds inhibited rabbit muscle glycogen phosphorylase b in the low micromolar range. The amide-1,2,3-triazole bioisosterism could not be verified for the ‘second’ NHCO part of N-acyl-N 0 -bD -glucopyranosyl ureas. 3. Experimental 3.1. General methods Melting points were measured in open capillary tubes or on a Kofler hot-stage and are uncorrected. Optical rotations were deter160 mined on a Perkin–Elmer 241 polarimeter at room temperature. NMR spectra were recorded with Bruker WP 360 SY (360/90 MHz for 1 H/ 13 C) and Varian UNITYINOVA 400 WB (400/100 MHz for 1 H/ 13 C) spectrometers. Chemical shifts are referenced to Me 4 Si as the internal reference ( 1 H) or the residual solvent signal ( 13 C). Thin-layer chromatography (TLC) was carried out on aluminum sheets coated with Silica Gel 60 F 254 (Merck). TLC plates were inspected by UV light (k= 254 nm) and after gentle heating for the carbohydrate derivatives. Silica gel column chromatography was Table 1 Inhibition of rabbit muscle glycogen phosphorylase b (RMGPb, K i [ l M]) O OH HO HO OH H N O N N N R R O HO HO HO O HH NH N O O R 975 28 4.6 4 10 No inhibition 29 0.35 4 11 34 CH3 CH 3 30 0.9 28 12 51 CF 3 31 1.8 4 13 143 C(CH 3 ) 3 32 0.7 4 O OH HO HO O HH N O N N N 33 179 25 R O OH HO HO OH H N O N O R X 21 172 a 22 no inhibition 23 X=O 24 X = S no inhibition N S N H N H 25 no inhibition 26 164 a 27 207 a a Calculated from the IC 50 values by the Cheng–Prusoff equation 29 :K i =IC 50 /(1 + [S]/K m ). B. Kónya et al. / Carbohydrate Research xxx (2012) xxx–xxx 3 CAR 6067 No. of Pages 9, Model 5G 8 February 2012 Please cite this article in press as: Kónya, B.; et al. Carbohydr. Res. (2012), doi:10.1016/j.carres.2012.01.020 performed with Silica Gel Si 60 (40–63 l m) purchased from Merck 170 (Darmstadt, Germany). Organic solutions were dried over anhydrous MgSO 4 , and concentrated at diminished pressure at 40– 50 °C (water bath). Aromatic aldoximes were prepared in the usual way 30 from the corresponding aldehydes purchased from SigmaAldrich. 3.2. N-Propynoyl-2,3,4,6-tetra-O-acetyl-bD -glucopyranosyl amine (3) 2,3,4,6-Tetra-O-acetyl-bD -glucopyranosylamine 20 (2,1g, 2.882 mmol) was dissolved in dry CH 2 Cl 2 (20 mL), propiolic acid (355 l L, 2 equiv) and DCC (0.565 g, 1.05 equiv) were added. The 180 mixture was stirred at rt and monitored by TLC (1:1 EtOAc–hexane). After consumption of the amine the solvent was evaporated and the residue was purified by column chromatography (eluent: 1:1 EtOAc–hexane) to give 1.01 g (88%) yellow syrup. R f = 0.5 (1:1 EtOAc–hexane); [ a ] D 31 (c0.22, CHCl 3 ); 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 7.27 (d, 1H, J= 9.0 Hz, NH), 5.20 (t, 1H, J= 9.4, 9.4 Hz, H-1), 5.03–4.80 (m, 2H, H-3, H-4), 4.19 (dd, 1H, J= 12.0, 3.3 Hz, H-6a), 4.00 (m, 2H, H-2, H-6b), 3.76 (ddd, 1H, J= 9.2, 5.0, 3.3 Hz, H-5), 2.97 (s, 1H, CH), 1.97, 1.95, 1.92, 1.91 (m, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 171.4, 171.3, 170.6, 190 170.3 (4xOCOCH 3 ), 153.0 (NHCO), 78.3 (C-1), 77.2 (CCH), 74.3, 73.6, 71.0, 68.7 (C-2–C-5), 61.1 (C-6), 49.7 (CCH), 21.7, 21.4 21.2, 21.2 (4 OCOCH 3 ). Anal. Calcd for C 17 H 21 NO 10 (399.35): C, 51.13; H, 5.30; N, 3.51. Found: C, 51.33; H, 5.12; N, 3.41. 3.3. General procedure for the Zemplén deacylation An O-peracylated compound (100 mg) was dissolved in dry MeOH (1 mL) and a solution of NaOMe (1 M in MeOH) was added to the solution in a catalytic amount. The reaction mixture was kept at rt. When the reaction was complete (TLC, 7:3 CHCl 3 –MeOH) the solution was neutralized with a cation exchange resin Amber200 lyst 15 (H + form). Filtration and removal of the solvent resulted in the corresponding deacetylated sugar derivative which, if necessary, was purified by column chromatography. 3.4. General procedures for the Cu(I) catalyzed azide–alkyne cycloaddition 3.4.1. In CH 2 Cl 2 –water mixtures with organic azides Equimolar amounts of N-propynoyl-2,3,4,6-tetra-O-acetyl-bD - glucopyranosylamine (3) and an azide were dissolved in CH 2 Cl 2 (7 mL/mmol alkyne). Water (the same volume as that of CH 2 Cl 2 ), CuSO 4 5H 2 O(5mol %), L -ascorbic-acid (15 mol %) were added and 210 the mixture was stirred at 50 °C and monitored by TLC (1:1 EtOAc–hexane). After disappearance of the starting materials the reaction mixture was diluted with water and CH 2 Cl 2 , the phases were separated, and the aqueous layer was washed with CH 2 Cl 2 (2 10 mL/mmol). The combined organic layer was dried, the solvent evaporated, and the residue purified by column chromatography (eluent: 1:1 EtOAc–hexane). 3.4.2. In CH 2 Cl 2 –water mixtures with organic azides prepared in situ from boronic acids Boronic acid (1 equiv) and NaN 3 (1.2 equiv) were dissolved in 220 MeOH (5 mL/mmol of boronic acid). CuSO 4 5H 2 O (0.10 equiv) was added and the mixture was stirred overnight at rt. CH 2 Cl 2 and water (10 mL of each/mmol of boronic acid), N-propynoyl2,3,4,6-tetra-O-acetyl-bD -glucopyranosylamine (3, 0.75 equiv) and L -ascorbic acid (0.5 equiv) were added and the reaction mixture was heated to 50 °C. After consumption of the alkyne (TLC, 1:1 EtOAc–hexane) the reaction mixture was diluted with water and CH 2 Cl 2 , the phases were separated and the aqueous layer was washed with CH 2 Cl 2 (2 10 mL/mmol). The combined organic layer was dried, the solvent evaporated, and the residue purified by 230 column chromatography (eluent: 1:1 EtOAc–hexane). 3.4.3. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-1-phenyl1,2,3-triazole-4-carboxamide (4) Prepared by general procedure given in Section 3.4.1 from 3 (335 mg, 0.841 mmol) and PhN 3 for 1 day. Yield: 396 mg (91%) white crystals. R f = 0.43 (1:1 EtOAc–hexane); Mp: 232–234 °C [ a ] D 6.9 (c0.54, DMSO) 1 H NMR (DMSO-d 6 , 360 MHz) d(ppm) 9.39 (s, 1H, triazole CH), 9.37 (br s, 1H, NH), 7.97 (d, 2H, J= 7.6 Hz, ArH), 7.64–7.54 (m, 3H, ArH), 5.66 (t, 1H, J= 9.1, 9.1 Hz, H-1), 5.41, 5.24, 4.92 (3 pseudo t, J= 9.1, 10.6 Hz in each, 240 H-2, H-3, H-4), 4.19–4.44 (m, 2H, H-6a, H-5), 4.01 (dd, 1H, J= 11.9, 3.0 Hz, H-6b), 2.01, 2.01, 1.95, 1.91 (4s, 12H, 4CH 3 ); 13 C NMR (DMSO-d 6 , 90 MHz) d(ppm) 171.0, 170.8, 169.9, 169.0 (CO), 157.3 (NHCO), 140.8 (triazole C-4), 129.2, 128.8, 128.8, 128.5, 125.5, 125.5 (Ar), 116.7 (triazole C-5), 78.1 (C-1), 73.9, 73.1, 70.6, 68.5 (C-2–C-5), 62.0 (C-6), 20.3, 20.2, 20.0 (CH 3 ). Anal. Calcd for C 23 H 26 N 4 O 10 (518.47): C, 53.28; H, 5.05; N, 10.81. Found: C, 52.88; H, 4.86; N, 10.94. 3.4.4. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-1-(2naphthyl)-1,2,3-triazole-4-carboxamide (5) 250 Prepared by general procedure given in Section 3.4.2 from 3 (696 mg, 1.744 mmol) and 2-naphthylazide (prepared in situ from naphthalene-2-boronic acid (300 mg, 1.744 mmol)). Yield: 743 mg (75%) white crystals. R f = 0.33 (1:1 EtOAc–hexane); Mp: 223– 225 °C[ a ] D 1.1 (c0.27, DMSO) 1 H NMR (CDCl 3 , 360 MHz) d (ppm) 8.61 (s, 1H, triazole CH), 8.14 (br s, 1H, NH), 7.89 (m, 5H, ArH), 7.55–7.52 (m, 2H, ArH), 5.45 (t, 1H, J= 9.3, 9.3 Hz, H-1), 5.31, 5.11, 5.10 (3 pseudo t, 1H each, J= 9.5, 10.5 Hz in each, H-2, H-3, H-4), 4.25 (dd, 1H, J= 12.2, 3.8 Hz, H-6a), 4.08 (dd, 1H, J= 12.2, 1.9 Hz, H-6b), 3.85 (m, 1H, H-5), 2.03, 1.99, 1.98, 1.96 260 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 170.8, 170.5, 170.2, 169.7 (CO), 160.3 (NHCO), 142.8 (triazole C-4), 133.9, 133.3, 130.5 128.5, 128.1, 127.9, 127.6, 119.2 (Ar), 118.8 (triazole C-5), 78.1 (C-1), 73.8, 73.2, 70.6, 68.3 (C-2–C-5), 61.8 (C-6), 20.9, 20.7 (CH 3 ). Anal. Calcd for C 27 H 28 N 4 O 10 (568.53): C, 57.04; H, 4.96; N, 9.85. Found: C, 56.64; H, 4.77; N, 9.98. 3.4.5. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-1-(3,5dimethyl-phenyl)-1,2,3-triazole-4-carboxamide (6) Prepared by general procedure given in Section 3.4.2 from 3 (798 mg, 2.00 mmol) and 3,5-dimethyl-phenyl-azide (prepared 270 in situ from 3,5-dimethyl-phenylboronic acid (300 mg, 2.00 mmol)). Yield: 852 mg (78%) yellow syrup. R f = 0.48 (1:1 EtOAc–hexane) [ a ] D 29 (c0.34, CHCl 3 ) 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 8.49 (s, 1H, triazole CH), 7.94 (d, 1H, J= 9.5 Hz, NH), 7.32 (s, 2H, ArH), 7.09 (s, 1H, ArH), 5.49 (t, 1H, J= 9.5, 9.5 Hz, H-1), 5.37, 5.16, 5.13 (3 pseudo t, 1H each, J= 9.5, 10.1 Hz in each, H-2, H-3, H-4), 4.30 (dd, 1H, J= 11.9, 4.0 Hz, H-6a), 4.13 (dd, 1H, J= 11.9, 1.9 Hz, H-6b), 3.90 (m, 1H, H-5), 2.39 (s, 6H, 2CH 3 ), 2.07, 2.03, 2.02, 1.99 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 170.8, 170.4, 170.2, 169.6 (CO), 160.4 (NHCO), 280 142.4 (triazole C-4), 140.1, 136.4, 136.4, 131.2, 131.2, 124.3 (Ar), 118.8 (triazole C-5), 78.0 (C-1), 73.7, 73.1, 70.5, 68.2 (C-2–C-5), 61.8 (C-6), 21.4, 21.4 (CH 3 ), 20.8, 20.7 (CH 3 ). Anal. Calcd for C 25 H 30 N 4 O 10 (546.53): C, 54.94; H, 5.53; N, 10.25. Found: C, 54.54; H, 5.34; N, 10.38. 3.4.6. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-1-(4trifluoromethyl-phenyl)-1,2,3-triazole-4-carboxamide (7) Prepared by general procedure given in Section 3.4.1 from 3 (426 mg, 1.069 mmol) and 4-CF 3 –C 6 H 4 –N 3 for 1 day. Yield: 495 mg (79%) colorless oil. R f = 0.48 (1:1 EtOAc–hexane) [ a ] D 4B. Kónya et al. / Carbohydrate Research xxx (2012) xxx–xxx CAR 6067 No. of Pages 9, Model 5G 8 February 2012 Please cite this article in press as: Kónya, B.; et al. Carbohydr. Res. (2012), doi:10.1016/j.carres.2012.01.020 290 1.2 (c0.30, DMSO) 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 8.77 (s, 1H, triazole CH), 8.12 (d, 1H, J= 9.5 Hz, NH), 7.97 (d, 2H, J= 8.4 Hz, ArH), 7.83 (d, 2H, J= 8.4 Hz, ArH), 5.56 (t, 1H, J= 9.4, 9.4 Hz, H-1), 5.40 (t, 1H, J= 9.7, 9.7 Hz, one of H-2, H-3, H-4), 5.18–5.05 (m, 2H, two of H-2, H-3, H-4), 4.30 (dd, 1H, J= 11.2, 4.0 Hz, H-6a), 4.10 (dd, 1H, J= 11.2, 4.0 Hz, H-6b), 3.96 (m, 1H, H-5), 2.05, 2.02, 2.00, 1.98 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 170.7, 170.5, 170.0, 169.9 (CO), 160.0 (NHCO), 143.0 (triazole C4), 138.8, 131.2 (q, C–CF 3 ,J= 34.9 Hz), 127.3, 126.0, 124.9, 124.4 (Ar), 121.9 (q, CF 3 ,J= 277 Hz), 120.8 (triazole C-5), 77.9 (C-1), 300 73.7, 73.0, 70.5, 68.2 (C-2–C-5), 61.7 (C-6), 20.7, 20.6 (CH 3 ). Anal. Calcd for C 24 H 25 F 3 N 4 O 10 (586.47): C, 49.15; H, 4.30; N, 9.55. Found: C, 48.75; H, 4.11; N, 9.69. 3.4.7. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-1-(4-tbutylphenyl)-1,2,3-triazole-4-carboxamide (8) Prepared by general procedure given in Section 3.4.1 from 3 (456 mg, 1.143 mmol) and 4-tBu–C 6 H 4 –N 3 for 1 day. Yield: 558 mg (85%) white crystals. R f = 0.49 (1:1 EtOAc–hexane); Mp: 194–196 °C[ a ] D 5.4 (c0.33, DMSO) 1 H NMR (CDCl 3 , 360 MHz) d (ppm) 8.55 (s, 1H, triazole CH), 8.00 (d, 1H, J= 9.5 Hz, NH), 7.64 310 (d, 2H, J= 8.6 Hz, ArH), 7.51 (d, 2H, J= 8.6 Hz, ArH), 5.52 (t, 1H, J= 9.5, 9.5 Hz, H-1), 5.36, 5.16, 5.10 (3 pseudo t, 1H each, J= 9.5, 9.5 Hz in each, H-2, H-3, H-4), 4.26 (dd, 1H, J= 11.2, 4.0 Hz, H6a), 4.08 (dd, 1H, J= 11.2, 2.1 Hz, H-6b), 3.90 (m, 1H, H-5), 2.02, 1.99, 1.99, 1.96 (4s, 12H, 4CH 3 ), 1.31 (s, 9H, C(CH 3 ) 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 170.7, 170.3, 170.1, 169.5 (CO), 160.4 (NHCO), 152.9 (Ar), 142.5 (triazole C-4), 134.0, 126.8, 126.8, 124.2, 124.2 (Ar), 120.4 (triazole C-5), 77.8 (C-1), 73.6, 73.1, 70.5, 68.2 (C-2–C-5), 61.8 (C-6), 34.9 (C(CH 3 ) 3 ), 31.2 (C(CH 3 ) 3 ), 20.7, 20.6 (CH 3 ). Anal. Calcd for C 27 H 34 N 4 O 10 (574.58): C, 56.44; H, 320 5.96; N, 9.75. Found: C, 56.20; H, 5.76; N, 9.94. 3.4.8. N-(bD -Glucopyranosyl)-1-phenyl-1,2,3-triazole-4carboxamide (9) Prepared by general procedure given in Section 3.3 from 4 (200 mg, 0.386 mmol) for 1 h. Yield: 119 mg (88%) white crystals. R f = 0.53 (7:3 CHCl 3 –MeOH); Mp: 199–201 °C[ a ] D +3.4 (c0.15, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 9.38 (s, 1H, triazole CH), 7.98 (d, 2H, J= 7.6 Hz, ArH), 7.58 (m, 3H, ArH), 4.89 (d, 1H, J= 8.9 Hz, H-1), 3.67 (dd, 1H, J= 12.3, 2.9 Hz, H-6a), 3.25– 3.09 (m, 5H, H-2, H-3, H-4, H-5, H-6b); 13 C NMR (DMSO330 d 6 +D 2 O, 90 MHz) d(ppm) 160.7 (NHCO), 143.4 (triazole C-4), 133.3, 131.7, 128.7, 127.9 (Ar), 118.4 (triazole C-5), 80.0 (C-1), 72.9, 71.2 70.1, 68.9 (C-2–C-5), 62.2 (C-6). Anal. Calcd for C 15 H 18 N 4 O 6 (350.33): C, 51.43; H, 5.18; N, 15.99. Found: C, 51.01; H, 4.98; N, 16.05. 3.4.9. N-(bD -Glucopyranosyl)-1-(2-naphthyl)-1,2,3-triazole-4carboxamide (10) Prepared by general procedure given in Section 3.3 from 5 (180 mg, 0.317 mmol) for 2 h. Yield: 77 mg (61%) white crystals. R f = 0.51 (7:3 CHCl 3 –MeOH); Mp: 275–277 °C (decomp.) [ a ] D +4.4 340 (c0.34, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 9.35 (s, 1H, triazole CH), 8.50 (s, 1H, ArH), 8.17 (d, 1H, J= 8.9 Hz, ArH), 8.12–7.98 (m, 3H, ArH), 7.69–7.59 (m, 2H, ArH), 4.95 (d, 1H, J= 9.0 Hz, H-1), 3.66 (dd, 1H, J= 10.9, 2.0 Hz, H-6a), 3.50–3.33 (m, 2H, H-3, H-6b), 3.29–3.10 (m, 3H, H-2, H-4, H-5); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 160.3 (NHCO), 142.0 (triazole C-4), 134.6, 131.9, 129.6, 129.4, 128.0, 127.7, 127.1, 124.4 (Ar), 119.1 (triazole C-5), 80.2 (C-1), 72.1, 71.3 70.1, 68.7 (C-2–C-5), 62.1 (C-6). Anal. Calcd for C 19 H 20 N 4 O 6 (400.39): C, 57.00; H, 5.03; N, 13.99. Found: C, 56.60; H, 4.86; N, 14.04. 350 3.4.10. N-(bD -Glucopyranosyl)-1-(3,5-dimethyl-phenyl)-1,2,3triazole-4-carboxamide (11) Prepared by general procedure given in Section 3.3 from 6 (180 mg, 0.317 mmol) for 1 h. Yield: 104 mg (87%) white crystals. R f = 0.74 (7:3 CHCl 3 –MeOH); Mp: 145–147 °C[ a ] D +1.7 (c0.33, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 9.15 (s, 1H, triazole CH), 7.52 (s, 2H, ArH), 7.15 (s, 1H, ArH), 4.93 (d, 1H, J= 9.0 Hz, H-1), 3.65 (dd, 1H, J= 11.0, 2.1 Hz, H-6a), 3.51–3.32 (m, 2H, H-3, H-6b), 3.31–3.12 (m, 3H, H-2, H-4, H-5), 2.34 (s, 6H, 2xCH 3 ); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 160.7 (NHCO), 360 143.3 (triazole C-4), 140.2, 136.5, 133.2, 127.1, 126.4, 126.0 (Ar), 118.3 (triazole C-5), 80.0 (C-1), 72.7, 71.2, 70.3, 68.8 (C-2–C-5), 61.9 (C-6). Anal. Calcd for C 17 H 22 N 4 O 6 (378.38): C, 53.96; H, 5.86; N, 14.81. Found: C, 53.56; H, 5.73; N, 14.94. 3.4.11. N-(bD -Glucopyranosyl)-1-(4-trifluoromethyl-phenyl)- 1,2,3-triazole-4-carboxamide (12) Prepared by general procedure given in Section 3.3 from 7 (200 mg, 0.341 mmol) for 2 h. Yield: 100 mg (70%) white crystals. R f = 0.57 (7:3 CHCl 3 –MeOH); Mp: 241–243 °C[ a ] D +4.5 (c0.60, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 9.35 (s, 1H, 370 triazole CH), 8.16 (d, 2H, J= 8.3 Hz, ArH), 7.98 (d, 2H, J= 8.6 Hz, ArH), 4.94 (d, 1H, J= 9.0 Hz, H-1), 3.64 (dd, 1H, J= 12.9, 2.4 Hz, H6a), 3.41–3.35 (m, 2H, H-3, H-6b), 3.29–3.06 (m, 3H, H-2, H-4, H5); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 160.5 (NHCO), 143.8 (triazole C-4), 139.4, 130.0, 129.7 (q, C–CF 3 ,J= 30.4 Hz), 128.0, 127.7, (Ar), 122.7 (q, CF 3 ,J= 273.2 Hz), 116.7 (triazole C-5), 80.0 (C-1), 72.4, 71.3, 70.4, 69.0 (C-2, C-3, C-4, C-5), 62.0 (C-6). Anal. Calcd for C 16 H 17 F 3 N 4 O 6 (418.32): C, 45.94; H, 4.10; N, 13.39. Found: C, 45.54; H, 3.91; N, 13.53. 3.4.12. N-(bD -Glucopyranosyl)-1-(4-tbutyl-phenyl)-1,2,3380 triazole-4-carboxamide (13) Prepared by general procedure given in Section 3.3 from 8 (200 mg, 0.348 mmol) for 2 hour. Yield: 111 mg (79%) white crystals. R f = 0.62 (7:3 CHCl 3 –MeOH); Mp: 207–209 °C[ a ] D +1.9 (c0.34, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 9.06 (s, 1H, triazol CH), 7.75 (d, 2H, J= 8.4 Hz, ArH), 7.58 (d, 2H, J= 8.5 Hz, ArH), 4.94 (d, 1H, J= 8.9 Hz, H-1), 3.65 (dd, 1H, J= 11.4, 2.3 Hz, H6a), 3.51–3.34 (m, 2H, H-3, H-6b), 3.23 (m, 3H, H-2, H-4, H-5), 1.25 (s, 9H, C(CH 3 ) 3 ); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 161.5 (NHCO), 153.4 (Ar), 143.5 (triazole C-4), 134.5, 127.9, 390 127.6, 121.4, 121.1 (Ar), 120.2 (triazole C-5), 80.3 (C-1), 72.1, 71.2, 70.3, 69.1 (C-2–C-5), 61.9 (C-6), 35.4 (C(CH 3 ) 3 ), 31.8 (C(CH 3 ) 3 ). Anal. Calcd for C 19 H 26 N 4 O 6 (406.43): C, 56.15; H, 6.45; N, 13.79. Found: C, 55.78; H, 6.25; N, 13.95. 3.5. General procedure for the nitrile-oxide cycloaddition A solution of N-propynoyl-2,3,4,6-tetra-O-acetyl-bD -glucopyranosyl-amine (0.5 mmol) and an arenecarbaldoxime (0.55 mmol, 1.1 equiv) in THF (4 mL) was stirred at rt under Argon. 0.2 M NaOCl solution (20 mL) was slowly added dropwise in 5 h with a syringe pump. The reaction was stirred at rt for an additional 12 h, then the 400 reaction mixture was diluted with water and EtOAc, the phases were separated and the aqueous layer was washed with EtOAc (2 30 mL/mmol). The combined organic layer was dried, the solvent evaporated, and the residue purified by column chromatography (eluent: 2:3 EtOAc–hexane). 3.5.1. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-3-phenylisoxazole-5-carboxamide (14) Prepared by general procedure given in Section 3.5 from 3 (248 mg, 0.621 mmol) and benzaldoxime (83 mg, 0.683 mmol). B. Kónya et al. / Carbohydrate Research xxx (2012) xxx–xxx 5 CAR 6067 No. of Pages 9, Model 5G 8 February 2012 Please cite this article in press as: Kónya, B.; et al. Carbohydr. Res. (2012), doi:10.1016/j.carres.2012.01.020 Yield: 177 mg (55%) white crystals. R f = 0.31 (2:3 EtOAc–hexane); 410 Mp: 212–214 °C[ a ] D 4(c0.21, CHCl 3 ) 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 7.82–7.79 (m, 2H, ArH), 7.41 (d, 1H, J= 9.2 Hz, NH), 7.40–7.35 (m, 3H, ArH), 7.20 (s, 1H, isoxazole CH), 5.37, 5.32, 5.07 (3 pseudo t, 4H, J= 9.5, 9.5 Hz in each, H-1, H-2, H-3, H-4), 4.30 (dd, 1H, J= 11.9, 2.8 Hz, H-6a), 4.14 (dd, 1H, J= 12.6, 2.2 Hz, H-6b) 3.82 (ddd, 1H, J= 9.2, 4.0, 2.6 Hz, H-5), 2.01, 1.98 (2s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 170.9, 170.7, 170.0, 169.6 (CO), 165.5 (isoxazole C-5), 162.6 (isoxazole C-3), 156.1 (NHCO), 130.8, 129.2, 129.2, 127.9, 127.0, 127.0 (Ar), 106.4 (isoxazole CH), 78.2 (C-1), 74.0, 72.8, 70.6, 68.2 (C-2–C-5), 420 61.7 (C-6), 20.8, 20.7 (OCOCH 3 ). Anal. Calcd for C 24 H 26 N 2 O 11 (518.47): C, 55.60; H, 5.05; N, 5.40. Found: C, 55.20; H, 4.87; N, 5.57. 3.5.2. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-3-(2naphthyl)-isoxazole-5-carboxamide (15) Prepared by general procedure given in Section 3.5 from 3 (388 mg, 0.972 mmol) and naphthalene-2-carbaldoxime (200 mg, 1.069 mmol). Yield: 288 mg (52%) white crystals. R f = 0.40 (2:3 EtOAc–hexane); Mp: 202–204 °C[ a ] D 7.8 (c0.24, CHCl 3 ) 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 8.12 (s, 1H, ArH), 7.83–7.76 (m, 430 4H, ArH), 7.62 (d, 1H, J= 9.2 Hz, NH), 7.46–7.43 (m, 2H, ArH), 7.31 (s, 1H, isoxazole CH), 5.42, 5.34, 5.12, 5.08 (4 pseudo t, 4H, J= 9.2, 9.5 Hz in each, H-1, H-2, H-3, H-4), 4.32 (dd, 1H, J= 11.9, 5.1 Hz, H-6a), 4.14 (dd, 1H, J= 11.9, 2.8 Hz, H-6b) 3.89 (ddd, 1H, J= 9.2, 5.1, 2.8 Hz, H-5), 2.00, 1.99, 1.98, 1.96 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 171.2, 171.0, 170.4, 170.0 (CO), 163.7 (isoxazole C-5), 163.0 (isoxazole C-3), 156.5 (NHCO), 134.6, 133.5, 129.4, 128.9, 128.2, 127.8, 127.4, 127.3, 125.5, 124.0 (Ar), 106.8 (isoxazole CH), 78.5 (C-1), 74.2, 73.2, 70.9, 68.5 (C-2– C-5), 62.1 (C-6), 21.1, 21.0 (CH 3 ). Anal. Calcd for C 28 H 28 N 2 O 11 440 (568.53): C, 59.15; H, 4.96; N, 4.93. Found: C, 58.85; H, 4.77; N, 5.07. 3.5.3. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-3-(benzo- [b]-furan-2-yl)-isoxazole-5-carboxamide (16) Prepared by general procedure given in Section 3.5 from 3 (200 mg, 0.501 mmol) and benzo-[b]-furan-2-carbaldoxime (89 mg, 1.551 mmol). Yield: 141 mg (50%) yellow oil. R f = 0.39 (2:3 EtOAc–hexane) [ a ] D 6.7 (c0.45, CHCl 3 ) 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 7.62–7.55 (m, 2H, ArH), 7.47 (d, 1H, J= 9.2 Hz, NH), 7.32–7.19 (m, 3H, ArH, isoxazole CH), 5.40, 5.33, 5.10, 5.08 450 (4 pseudo t, 4H, J= 9.2, 9.5 Hz in each, H-1, H-2, H-3, H-4), 4.27 (dd, 1H, J= 12.1, 5.2 Hz, H-6a), 4.06 (dd, 1H, J= 12.1, 2.8 Hz, H6b), 3.84 (ddd, 1H, J= 9.2, 5.2, 2.8 Hz, H-5), 2.01, 1.99, 1.98, 1.96 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 170.9, 170.7, 170.0, 169.6 (CO), 162.6 (isoxazole C-5), 156.0 (isoxazole C-3), 155.7 (NHCO), 155.4, 144.5, 127.8, 126.4, 123.8, 122.0 (Ar), 106.3 (isoxazole CH), 78.2 (C-1), 74.0, 72.9, 70.6, 68.2 (C-2–C-5), 61.7 (C-6), 20.8, 20.7 (CH 3 ). Anal. Calcd for C 26 H 26 N 2 O 12 (558.49): C, 55.91; H, 4.69; N, 5.02. Found: C, 55.50; H, 4.50; N, 5.18. 3.5.4. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-3-(benzo460 [b]-thiophen-2-yl)-isoxazole-5-carboxamide (17) Prepared by general procedure given in Section 3.5 from 3 (204 mg, 0.513 mmol) and benzo-[b]-thiophen-2-carbaldoxime (100 mg, 0.564 mmol). Yield: 151 mg (51%) yellow crystals. R f = 0.29 (2:3 EtOAc–hexane); Mp: 192–194 °C (decomp.) [ a ] D 7 (c0.21, CHCl 3 ) 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 7.77 (d, 1H, J= 9.3 Hz, NH), 7.70–7.68 (m, 2H, ArH), 7.59 (s, 1H, ArH), 7.32– 7.29 (m, 2H, ArH), 7.21 (s, 1H, isoxazole CH), 5.40, 5.33, 5.11, 5.07 (4 pseudo t, 4H, J= 9.2, 9.5 Hz in each, H-1, H-2, H-3, H-4), 4.32 (dd, 1H, J= 12.0, 2.9 Hz, H-6a), 4.13 (dd, 1H, J= 12.0, 5.3 Hz, 470 H-6b), 3.90 (ddd, 1H, J= 9.2, 5.3, 2.9 Hz, H-5), 2.00, 1.99, 1.98, 1.96 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 171.0, 170.8, 170.0, 169.6 (CO), 162.7 (isoxazole C-5), 159.0 (isoxazole C-3), 155.9 (NHCO), 129.3, 126.2, 125.6, 125.0, 124.5, 122.6 (Ar), 106.4 (isoxazole CH), 78.2 (C-1), 73.9, 72.9, 70.6, 68.2 (C-2–C-5), 61.8 (C-6), 20.8, 20.7, 20.6 (CH 3 ). Anal. Calcd for C 26 H 26 N 2 O 11 S (574.56): C, 54.35; H, 4.56; N, 4.88. Found: C, 53.93; H, 4.36; N, 5.03. 3.5.5. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-3-(benzo- [b]-thiazol-2-yl)-isoxazole-5-carboxamide (18) 480 Prepared by general procedure given in Section 3.5 from 3 (200 mg, 0.501 mmol) and benzo-[b]-thiazol-2-carbaldoxime (98 mg, 0.551 mmol). Yield: 86 mg (30%) white crystals. R f = 0.39 (2:3 EtOAc–hexane); Mp: 179–181 °C[ a ] D 7.6 (c0.19, CHCl 3 ) 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 8.10 (d, 1H, J= 9.2 Hz, NH) 8.01 (m, 2H, ArH), 7.59–7.52 (m, 2H, ArH), 7.27 (s, 1H, isoxazole CH), 5.47, 5.39, 5.18, 5.14 (4 pseudo t, 4H, J= 9.2, 9.6 Hz each, H1, H-2, H-3, H-4), 4.38 (dd, 1H, J= 11.9, 5.3 Hz, H-6a), 4.17 (dd, 1H, J= 11.9, 2.8 Hz, H-6b), 3.94 (ddd, 1H, J= 9.2, 5.3, 2.8 Hz, H-5), 2.06, 2.06, 2.04, 2.03 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 490 90 MHz) d(ppm) 171.0, 170.8, 170.0, 169.6 (CO), 162.4 (isoxazole C-5), 161.1 (benzothiazole C-2), 158.3 (isoxazole C-3), 156.3 (NHCO), 152.5, 136.3, 126.9, 125.5, 123.7, 122.7 (Ar), 102.8 (isoxazole CH), 78.0 (C-1), 73.8, 72.6, 71.0, 68.8 (C-2–C-5), 61.8 (C-6), 20.8, 20.7, 20.6 (CH 3 ). Anal. Calcd for C 25 H 25 N 3 O 11 S (575.54): C, 52.17; H, 4.38; N, 7.30. Found: C, 51.87; H, 4.20; N, 7.45. 3.5.6. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-3-(indol-2yl)-isoxazole-5-carboxamide (19) Prepared by general procedure given in Section 3.5 from 3 (300 mg, 0.752 mmol) and indol-2-carbaldoxime (132 mg, 500 0.827 mmol). Yield: 100 mg (24%) yellow oil. R f = 0.44 (2:3 EtOAc–hexane) [ a ] D 8.1 (c0.23, CHCl 3 ) 1 H NMR (CDCl 3 , 360 MHz) d(ppm) 8.24 (s, 1H, indol NH), 7.70–7.41 (m, 5H, ArH, indol CH), 7.29 (s, 1H, isoxazole CH), 5.50, 5.42, 5.15, 5.11 (4 pseudo t, 4H, J= 9.2, 9.6 Hz each, H-1, H-2, H-3, H-4), 4.35 (dd, 1H, J= 11.9, 5.3 Hz, H-6a), 4.22 (dd, 1H, J= 11.9, 2.9 Hz, H-6b), 4.00 (ddd, 1H, J= 9.2, 5.3, 2.9 Hz, H-5), 2.02, 2.00, 1.99, 1.98 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 171.2, 170.8, 170.1, 169.5 (CO), 162.6 (isoxazole C-5), 158.8 (isoxazole C-3), 156.9 (NHCO), 137.1, 135.2, 128.4, 122.6, 121.9, 121.3 118.4 (Ar, indol C-2), 510 101.0, 100.2 (isoxazole CH, indol CH), 78.1 (C-1), 74.0, 72.7, 71.0, 68.4 (C-2–C-5), 61.9 (C-6), 20.5, 20.5, 20.4, 20.4 (CH 3 ). Anal. Calcd for C 26 H 27 N 3 O 11 (557.51): C, 56.01; H, 4.88; N, 7.54. Found: C, 55.61; H, 4.69; N, 7.68. 3.5.7. N-(2,3,4,6-Tetra-O-acetyl-bD -glucopyranosyl)-3-(indol-3yl)-isoxazole-5-carboxamide (20) Prepared by general procedure given in Section 3.5 from 3 (400 mg, 1.00 mmol) and indol-3-carbaldoxime (177 mg, 1.10 mmol). Yield: 110 mg (20%) yellow oil. R f = 0.49 (2:3 EtOAc– hexane) [ a ] D 5.6 (c0.15, CHCl 3 ) 1 H NMR (CDCl 3 , 360 MHz) d 520 (ppm) 7.75 (s, 1H, indol NH), 7.64–7.36 (m, 5H, ArH, indol CH), 7.28 (s, 1H, isoxazole CH), 5.49, 5.40, 5.17, 5.10 (4 pseudo t, 4H, J= 9.2, 9.6 Hz each, H-1, H-2, H-3, H-4), 4.24 (dd, 1H, J= 11.9, 5.3 Hz, H-6a), 4.19 (dd, 1H, J= 11.9, 3.0 Hz, H-6b), 4.01 (ddd, 1H, J= 9.2, 5.3, 3.0 Hz, H-5), 2.02, 2.00, 1.99, 1.98 (4s, 12H, 4CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm) 171.4, 171.2, 170.4, 170.0 (CO), 164.9 (isoxazole C-5), 160.0 (isoxazole C-3), 156.1 (NHCO), 139.1, 133.0, 125.5, 121.5, 120.0, 119.6 112.8 (Ar, indol C-2), 101.9, 101.0 (isoxazole CH, indol CH), 78.5 (C-1), 73.7, 73.0, 71.1, 68.2 (C-2–C-5), 61.5 (C-6), 20.7, 20.6 (CH 3 ). Anal. Calcd for 530 C 26 H 27 N 3 O 11 (557.51): C, 56.01; H, 4.88; N, 7.54. Found: C, 55.32; H, 4.59; N, 7.64. 6B. Kónya et al. / Carbohydrate Research xxx (2012) xxx–xxx CAR 6067 No. of Pages 9, Model 5G 8 February 2012 Please cite this article in press as: Kónya, B.; et al. Carbohydr. Res. (2012), doi:10.1016/j.carres.2012.01.020 3.5.8. N-(bD -Glucopyranosyl)-3-phenyl-isoxazole-5carboxamide (21) Prepared by general procedure given in Section 3.3 from 14 (80 mg, 0.154 mmol) for 1 hour. Yield: 52 mg (97%) white solid. R f = 0.47 (7:3 CHCl 3 –MeOH); Mp: 215–217 °C (decomp.) [ a ] D +7.8 (c0.23, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 7.92–7.90 (m, 2H, ArH), 7.80 (s, 1H, isoxazole CH), 7.55–7.53 (m, 3H, ArH), 4.88 (t, 1H, J= 9.3, 9.3 Hz, H-1), 3.68–3.35 (m, 3H, H-6a, 540 H-2, H-3), 3.27–3.08 (m, 3H, H-6b, H-5, H-4); 13 C NMR (DMSOd 6 +D 2 O, 90 MHz) d(ppm) 164.0 (isoxazole C-5), 162.5 (isoxazole C-3), 156.2 (NHCO), 130.8, 130.7, 129.4, 129.3, 127.9, 126.7, (Ar), 105.0 (isoxazole CH), 80.1 (C-1), 79.0, 77.3, 71.6, 69.9 (C-2–C-5), 61.0 (C-6). Anal. Calcd for C 16 H 18 N 2 O 7 (350.32): C, 54.86; H, 5.18; N, 8.00. Found: C, 54.47; H, 5.00; N, 8.14. 3.5.9. N-(bD -Glucopyranosyl)-3-(2-naphthyl)-isoxazole-5carboxamide (22) Prepared by general procedure given in Section 3.3 from 15 (160 mg, 0.281 mmol) for 1.5 h. Yield: 102 mg (91%) white solid. 550 R f = 0.51 (7:3 CHCl 3 –MeOH); Mp: 218–220 °C (decomp.) [ a ] D +6.0 (c0.25, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 8.54 (s, 1H, ArH), 8.10–7.99 (m, 4H, ArH), 7.88 (s, 1H, isoxazole CH), 7.65–7.62 (m, 2H, ArH), 5.12–4.93 (m, 4H, H-1, H-2, H-3, H-4), 3.70 (dd, 1H, J= 12.0, 5.0 Hz, H-6a), 3.22 (ddd, 1H, J= 9.0, 5.0, 3.0 Hz, H-5), 3.12 (dd, 1H, J= 12.0, 3.0 Hz, H-6b); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 164.0 (isoxazole C-5), 162.2 (isoxazole C-3), 156.0 (NHCO), 133.8, 132.9, 129.0, 128.6, 128.6, 127.9, 127.6, 127.1, 127.0, 126.9, 125.2, 123.5 (Ar), 105.4 (isoxazole CH), 79.8 (C-1), 79.0, 77.5, 71.9, 70.0 (C-2–C-5), 61.0 (C-6). Anal. 560 Calcd for C 20 H 20 N 2 O 7 (400.38): C, 60.00; H, 5.03; N, 7.00. Found: C, 59.64; H, 4.89; N, 7.20. 3.5.10. N-(bD -Glucopyranosyl)-3-(benzo-[b]-furan-2-yl)- isoxazole-5-carboxamide (23) Prepared by general procedure given in Section 3.3 from 16 (120 mg, 0.215 mmol) for 1 h. Yield: 74 mg (88%) yellow solid. R f = 0.55 (7:3 CHCl 3 –MeOH); Mp: 196–198 °C[ a ] D +9 (c0.18, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 7.79–7.72 (m, 4H, ArH, benzofuran CH, isoxazole CH), 7.48–7.33 (m, 2H, ArH), 4.87 (d, 1H, J= 9.3 Hz, H-1), 3.46–3.10 (m, 6H, H-2, H-3, H570 4, H-5, H-6a, H-6b); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 164.0 (isoxazole C-5), 155.0 (isoxazole C-3), 154.9 (NHCO), 154.6 (benzofuran C-2), 145.6, 127.5, 126.6, 123.9, 123.0, 122.4 (Ar), 111.8 (benzofuran C-3), 108.9 (isoxazole CH), 79.9 (C-1), 79.0, 77.4, 71.9, 69.9 (C-2–C-5), 60.9 (C-6). Anal. Calcd for C 18 H 18 N 2 O 8 (390.34): C, 55.39; H, 4.65; N, 7.18. Found: C, 54.89; H, 4.46; N, 7.32. 3.5.11. N-(bD -Glucopyranosyl)-3-(benzo-[b]-thiophen-2-yl)- isoxazole-5-carboxamide (24) Prepared by general procedure given in Section 3.3 from 17 580 (120 mg, 0.209 mmol) for 1 h. Yield: 81 mg (95%) yellow solid. R f = 0.51 (7:3 CHCl 3 –MeOH); Mp: 234–236 °C[ a ] D +7.8 (c0.25, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 8.16 (s, 1H, benzothiophen CH), 8.08–7.95 (m, 2H, ArH), 7.83 (s, 1H, isoxazole CH), 7.48–7.46 (m, 2H, ArH), 5.07 (d, 1H, J= 9.2 Hz, H-1), 4.97– 4.91 (m, 2H, H-2, H-3), 3.70 (ddd, 1H, J= 9.0, 3.7, 2.6 Hz, H-5), 3.46–3.17 (m, 3H, H-4, H-6a, H-6b); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 163.9 (isoxazole C-5), 155.7 (isoxazole C-3), 155.0 (NHCO), 154.8 (benzothiophen C-2), 144.6, 127.6, 126.6, 124.0, 122.3, 122.0 (Ar), 112.0 (benzothiophen C-3), 109.0 (isoxaz590 ole CH), 80.0 (C-1), 79.2, 77.4, 72.0, 70.0 (C-2–C-5), 61.0 (C-6). Anal. Calcd for C 18 H 18 N 2 O 7 S (406.41): C, 53.20; H, 4.46; N, 6.89. Found: C, 52.81; H, 4.28; N, 7.03. 3.5.12. N-(bD -Glucopyranosyl)-3-(benzo-[b]-thiazol-2-yl)- isoxazole-5-carboxamide (25) Prepared by general procedure given in Section 3.3 from 18 (80 mg, 0.139 mmol) for 1 h. Yield: 51 mg (90%) yellow solid. R f = 0.55 (7:3 CHCl 3 –MeOH); Mp: 223–225 °C[ a ] D +5.8 (c0.19, DMSO) 1 H NMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 7.90–7.82 (m, 2H, ArH), 7.78 (s, 1H, isoxazole CH), 7.67–7.51 (m, 2H, ArH), 600 4.78 (t, 1H, J= 9.3, 9.3 Hz, H-1), 4.60–4.44 (m, 2H, H-2, H-3), 3.54–3.31 (m, 3H, H-6a, H-6b, H-4), 3.22 (ddd, 1H, J= 9.3, 4.0, 2.3 Hz, H-5); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 166.5 (isoxazole C-5), 161.9 (isoxazole C-3), 160.3 (benzothiazole C-2), 158.9 (NHCO), 150.4, 136.5, 127.3, 126.3, 125.5, 123.2 (Ar), 108.4 (isoxazole CH), 81.8 (C-1), 73.6, 71.5, 70.9, 69.7 (C-2–C-5), 62.5 (C-6). Anal. Calcd for C 17 H 17 N 3 O 7 S (407.40): C, 50.12; H, 4.21; N, 10.31. Found: C, 49.72; H, 4.03; N, 10.50. 3.5.13. N-(bD -Glucopyranosyl)-3-(indol-2-yl)-isoxazole-5carboxamide (26) 610 Prepared by general procedure given in Section 3.3 from 19 (100 mg, 0.179 mmol) for 2 h. Yield: 53 mg (76%) yellow oil. R f = 0.45 (7:3 CHCl 3 –MeOH) [ a ] D +1 (c0.10, DMSO) 1 HNMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 7.61–7.51 (m, 3H, ArH, isoxazole CH), 7.35–7.19 (m, 2H, ArH,indol CH), 4.97 (d, 1H, J= 10.6 Hz, H-1), 3.50–3.07 (m, 6H, H-2, H-3, H-4, H-5, H-6a, H-6b); 13 CNMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 164.0 (isoxazole C-5), 156.8 (isoxazole C-3), 155.4 (NHCO), 147.9, 136.0, 132.3, 125.9, 123.6, 121.5, 118.9 (Ar, indol C-2), 113.3, 110.2 (isoxazole CH, indol CH), 80.6 (C-1), 79.9, 77.7, 73.0, 70.3 (C-2–C-5), 61.6 (C-6). Anal. Calcd 620 for C 18 H 19 N 3 O 7 (389.36): C, 55.53; H, 4.92; N, 10.79. Found: C, 55.13; H, 4.73; N, 10.93. 3.5.14. N-(bD -Glucopyranosyl)-3-(indol-3-yl)-isoxazole-5carboxamide (27) Prepared by general procedure given in Section 3.3 from 20 (100 mg, 0.179 mmol) for 1.5 h. Yield: 49 mg (70%) yellow oil. R f = 0.40 (7:3 CHCl 3 –MeOH) [ a ] D +3 (c0.10, DMSO) 1 HNMR (DMSO-d 6 +D 2 O, 360 MHz) d(ppm) 7.90 (s, 1H, isoxazole CH), 7.60–7.42 (m, 2H, ArH), 7.34–7.02 (m, 3H, ArH, indol CH), 4.96 (d, 1H, J= 9.2 Hz, H-1), 3.53–3.12 (m, 6H, H-2, H-3, H-4, H-5, H-6a, 630 H-6b); 13 C NMR (DMSO-d 6 +D 2 O, 90 MHz) d(ppm) 163.6 (isoxazole C-5), 157.2 (isoxazole C-3), 156.0 (NHCO), 139.1, 133.0, 129.8, 125.6, 124.0, 122.0, 119.1 (Ar, indol C-2), 111.9, 107.3 (isoxazole CH, indol CH), 80.2 (C-1), 79.7, 78.2, 72.4, 69.9 (C-2–C-5), 61.0 (C6). Anal. Calcd for C 18 H 19 N 3 O 7 (389.36): C, 55.53; H, 4.92; N, 10.79. Found: C, 55.25; H, 4.69; N, 10.88. Acknowledgements This work was supported by the Hungarian Scientific Research Fund (OTKA CK77712, CNK80709) and TÁMOP 4.2.1./B-09/1/ KONV-2010-0007 project implemented through the New Hungary 640 Development Plan, co-financed by the European Social Fund. Some compounds were made during a stay of BK at the University of Lyon with J.-P. Praly supported by a joint program of French CNRS and the Hungarian Academy of Sciences (PICS 4576). The authors thank K. E. Kövér for her advice on HMBC spectra. References 1. Kurukulasuriya, R.; Link, J. T.; Madar, D. J.; Pei, Z.; Rohde, J. J.; Richards, S. J.; Souers, A. J.; Szczepankiewicz, B. G. Curr. Med. Chem. 2003,10, 99–121. 2. Barf, T. Mini-Rev. Med. Chem. 2004,4, 897–908. 3. Ross, S. A.; Gulve, E. A.; Wang, M. H. Chem. Rev. 2004,104, 1255–1282. 6504. Somsák, L.; Czifrák, K.; Tóth, M.; Bokor, É.; Chrysina, E. D.; Alexacou, K. M.; Hayes, J. M.; Tiraidis, C.; Lazoura, E.; Leonidas, D. D.; Zographos, S. E.; Oikonomakos, N. G. Curr. Med. Chem. 2008,15, 2933–2983. B. Kónya et al. / Carbohydrate Research xxx (2012) xxx–xxx 7 CAR 6067 No. of Pages 9, Model 5G 8 February 2012 Please cite this article in press as: Kónya, B.; et al. Carbohydr. Res. (2012), doi:10.1016/j.carres.2012.01.020