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Four 2,4-dioxohexahydro-1,3,5-triazine O-acetylglycosyl glucosides were synthesized through glucoside formation reactions at room temperature using 4-dimethylaminopyridine as a catalyst and triethylamine as a deacidification reagent. Their structure was confirmed by IR, 1 H NMR spectra, MS, and elemental analysis. The synthesized compounds are all of β-configuration. The results show that DMAP is an effective catalyst; the yields can reach 83.7%. The above glucosides showed an improved antiviral activity against tobacco mosaic virus.We have synthesized 2,4-dioxohexahydro-1,3,5-triazine (DHT) derivatives, which possess certain activities against tobacco mosaic virus (TMV) [1][2][3][4].A number of authors have reported the bioactivity of glucosides. They have been used in medicinal chemistry and agriculture [5][6][7][8][9][10][11][12].4-Dimethylaminopyridine (DMAP) is widely used in organic synthesis as a nucleophilic reaction catalyst [13,14]. It can efficiently catalyze esterification reactions, but it has been rarely reported as a catalyst for the synthesis of 2,4-dioxohexahydro-1,3,5-triazine O-acetylglycosyl glucosides. In view of the above and in connection with our recent work on the search for new phytoantiviral agents [15][16][17], we selected DMAP as a catalyst and Et 3 N as a deacidification reagent for the preparation of glucosides 1-4 (Scheme 1, Table).We found that the reactions in the presence of DMAP/Et 3 N proceeded quickly and smoothly at room temperature under mild conditions and with a substantially increased yield (up to 83.7%), and a decrease in the reaction time compared with the phase-transfer catalyst (Bu 4 NBr) method. This method is simple, and the amount of catalyst DMAP is small. Optimum reaction conditions were as follows: 1.5-2.5 h at 20-25°C with equimolar ratio of reagents (5 ml of Et 3 N and 1.5 mmol of DMAP for 0.03 mol of DHT and 0.03 mol of α-O-acetyl-glycosyl bromide).

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Six benzimidazolylphenoxyacetic acid O-acetylxylopyranosyl and O-acetylgalactopyranosyl esters were synthesized through esterification reactions at room temperature using 4-dimethylaminopyridine as a catalyst and triethylamine as a deacidification reagent. Their structure was confirmed by IR, 1 H NMR spectra, MS, and elemental analysis. The synthesized compounds are all of β-configuration. The results show that DMAP is an effective catalyst; the yields can reach 63.6%. The above esters showed improved antiviral activity against tobacco mosaic virus. Keywords: O-acetylgalactopyranosyl esters, O-acetylxylopyranosyl esters, benzimidazolylphenoxyacetic acid esters, tobacco mosaic virus, DMAP/Et 3 N.A number of authors have reported the bioactivity of benzimidazole and its derivatives. They are applied widely in medicinal chemistry, agriculture, and also as plant virus inhibitors [1][2][3][4].4-Dimethylaminopyridine (DMAP) is widely used in organic synthesis as a nucleophilic reaction catalyst [5,6]. It can efficiently catalyze esterification reactions, but it has been rarely reported as a catalyst for the synthesis of benzimidazolylphenoxyacetic acid esters. In view of the above, and in connection with our recent work on the search for new phytoantiviral agents [7,8], we selected DMAP as a catalyst and Et 3 N as a deacidification reagent for the preparation of saccharide esters 1-6.The reactions are shown in Scheme 1, and the results are summarized in Table 1. We found that the reactions in the presence of DMAP/Et 3 N proceeded quickly and smoothly at room temperature under mild conditions and with a substantially increased yield (up to 63.6%), and decrease in reaction time compared with the phase-transfer catalyst (Bu 4 NBr) method. This method is simple; the amount of catalyst DMAP is small. Optimum reaction conditions were as follows: 1.5-2.5 h at 20-25°C with equimolar ratio of reagents (1 ml of Et 3 N and 0.3 mmol of DMAP for 5.25 mmol of acid).The antiviral activity of benzimidazolylphenoxyacetic acid esters (43-58%) against tobacco mosaic virus (TMV) is higher than that of the parent acids (about 30% [8]), xylopyranosyl derivatives being more active than galactopyranosyl analogues (Table 1).As far as we know, this is the first example of benzimidazolylphenoxyacetic acid saccharide esters synthesized using the DMAP/Et 3 N method. We propose (Scheme 2) that DMAP first reacted with O-acetylglycosyl bromide, quickly forming an unstable intermediate (DMAP salt), with increased __________________________________________________________________________________________

Carbohydrates U 0500 Efficient Synthesis of Benzimidazolylphenoxyacetic Acid O-Acetylxylopyranosyl and O-Acetylgalactopyranosyl Esters and Their AntiviralActivity. -The 6 title esters show improved antiviral activity against the tobacco mosaic virus compared to the respective parent acids. -(CHEN, H.; SONG, W.; HUANG*, S.; Chem.