A Facile and Practical Synthesis of 9-Methyl-3-(1H-tetrazol-5-yl)-4H-pyrido(1,2-a)pyrimidin-4-one.
作者:Atsunori SANO、Masami ISHIHARA、Jun YOSHIHARA、Motoshige SUMINO、Hiromi NAWA
DOI:10.1248/cpb.43.683
日期:——
A facile and practical synthesis of 9-methyl-3-(1H-tetrazol-5-yl)-4H-pyrido[1, 2-α]pyrimidin-4-one (4), the potassium salt of which is used clinically as an anti-asthma agent, is described. Treatment of a key intermediate (6b), prepared from 2-amino-3-methylpyridine (1) and 2-ethoxymethylene-1, 3-propanedinitrile, with sodium azide in N, N-dimethylformamide gave predominantly the cyanotetrazole (7a), while in acetic acid it gave exclusively the iminotetrazole (7b), which was easily converted into 4 by acid hydrolysis. A one-pot process starting from 6b to give 4, avoiding the use of explosive aluminum azide, was established.
9-甲基-3-(1H-四唑-5-基)-4H-吡啶并[1, 2-α]嘧啶-4-酮(4)的简便实用合成,其钾盐在临床上用作描述了一种抗哮喘剂。用叠氮化钠在 N,N-二甲基甲酰胺中处理由 2-氨基-3-甲基吡啶 (1) 和 2-乙氧基亚甲基-1, 3-丙二腈制备的关键中间体 (6b),主要得到氰基四唑 (7a),同时在乙酸中仅生成亚胺四唑 (7b),很容易通过酸水解转化为 4。建立了从6b开始得到4的一锅法,避免使用爆炸性叠氮化铝。