L-鼠李糖基(氨基)硫脲类化合物的合成

以L-鼠李糖为起始原料, 制备1-溴-2,3,4-三-O-乙酰基-β-L-吡喃型鼠李糖, 然后在甲苯中与Pb(SCN)₂作用, 得到中间体2,3,4-三-O-乙酰基-α-L-吡喃型鼠李糖基异硫氰酸酯(1). 利用2,3,4-三-O-乙酰基-α-L-吡喃型鼠李糖基异硫氰酸酯易发生亲核加成的性质, 在不同溶剂中, 与取代的苯并噻唑胺(2a～2f)、取代的苯并噻唑肼(2g～2l)、氧化和非氧化的哒嗪酮甲酰肼(2m, 2n)以及取代的嘧啶胺(2o, 2p)反应, 合成了16种新的(氨基)硫脲类化合物3a～3p. 所有化合物的结构均经IR, ¹H NMR, LC-MS和元素分析确证, 并对它们的生物活性做了初步测试.

Synthesis of L-Rhamnosyl(amino)thiourea De-rivatives

The starting material L-rhamnose was converted into 2,3,4-tri-O-acetyl-β-L-rhamnopyranosyl bromide in good yield by treating with ace-tic anhydride and then Br₂. The key intermediate 2,3,4-tri-O- ace-tyl-α-L-rhamnopyranosyl isothiocyanate was obtained by reaction of triace-tyl-β-L-rhamnosyl bromide with Pb(SCN)₂ in boiling toluene. The nucleophilic addition of rhamnosyl isothiocyanate to substituted 2-aminobenzothiazoles (2a～2f), 2-hydrazinobenzothiazoles (2g～2l), oxidized and nonoxidized 3-hydra- zinocar-bonyl-pyridazin-6-ones (2m, 2n) and 2-aminopyrimidines(2o, 2p) in dif-ferent solvent system afforded a series of rhamnosyl thioureas and thiosemicarbazides respectively. The structures of all 16 new compounds 3a～3p have been confirmed by IR, ¹H NMR, LC-MS spectra and elemental analysis. Biological activity has been elementarily evaluated.