The patent relates to a new process of synthesis of an antihypertensive agent, N-pentanoyl-N-[[2'-(1H-tetrazole-5-yl)[1,1'-biphenyl]-4-yl]methyl]-L-valine (1), also known under the generic name of valsartan, by selective reaction of N-pentanoyl-N-[[2'-(1H-tetrazole-5-yl) [1,1'-biphenyl]-4-yl]methyl]-L-valine methyl-ester (14) with metallic or quaternary ammonium trialkylsilanolates by SN2 reaction. The compound 14 was produced in four reaction steps starting from 2N-trityl-5-(4'-methylbiphenyl-2-yl)tetrazole (17) and L-valine methyl-ester (11). Free-radical bromination of the compound 17 with N-bromosuccinimide produced 2N-trityl-5-(4'-bromomethylbiphenyl-2-yl)tetrazole (7), which in the reaction with L-valine methyl-ester (11) results in N-[[2'-(2N-trityl-tetrazole-5-yl)[1,1'-biphenyl]-4yl]methyl]-L-valine methyl-ester hydrobromide (15). Acylation of the compound 15 with pentanoyl chloride in the presence of trialkylamine bases results in N-pentanoyl-N-[[2'-(2Ntrityl-tetrazole-5-yl)[1,1'-biphenyl] -4-yl]methyl]-L-valine methyl-ester (16). Removal of trityl protecting group by strong acids produces the key intermediary, compound 14.
该专利涉及一种新的合成抗高血压药物N-戊酰-N-[[2'-(
1H-四唑-5-基)[1,1'-
联苯]-4-基]甲基]-
L-缬氨酸(1),通用名称为
缬沙坦,通过N-戊酰-N-[[2'-(
1H-四唑-5-基)[1,1'-
联苯]-4-基]甲基]-
L-缬氨酸甲酯(14)与
金属或季
铵三烷基
硅醇盐进行SN2反应的选择性反应而制备。化合物14经过四个反应步骤制备,起始原料为2N-三苄基-5-(4'-甲基
联苯基-2-基)
四唑(17)和
L-缬氨酸甲酯(11)。化合物17与N-
溴代琥珀
酰亚胺自由基
溴化反应产生2N-三苄基-5-(4'-
溴甲基联苯基-2-基)
四唑(7),该化合物与
L-缬氨酸甲酯(11)反应得到N-[[2'-(2N-三苄基-
四唑-5-基)[1,1'-
联苯]-4-基]甲基]-
L-缬氨酸甲酯溴化氢盐(15)。化合物15与
戊酰氯在
三烷基胺碱存在下酰基化反应得到N-戊酰-N-[[2'-(2N-三苄基-
四唑-5-基)[1,1'-
联苯]-4-基]甲基]-
L-缬氨酸甲酯(16)。用强酸去除三苄基保护基团产生关键中间体化合物14。