申请人:Martin Pierre
公开号:US20090118512A1
公开(公告)日:2009-05-07
6,7-Dihydro-5H-imidazo[1,5-a]pyridin-8-one (I), is obtainable in high yields by: 1) a process which proceeds from a suitably protected C-(3-hydroxypyridin-2-yl)methylamine whose amine is converted to the formamide which is then cyclized to the imidazo[1,5-a]pyridine and hydrogenated to the 6,7-dihydro-5H-imidazo[1,5-a]pyridin-8-one, and suitably protected C-(3-hydroxypyridin-2-yl)methylamines can be prepared either in 2 steps proceeding from commercially available 3-hydroxy-2-cyanopyridine [932-35-4] or in 3 steps proceeding from commercially available 2-hydroxymethylpyridin-3-ol [14173-30-9]; 2) a process for preparing 4-hydroxy-1-(1H-imidazol-4-yl)butan-1-one, an intermediate from the synthesis of 6,7-dihydro-5H-imidazo[1,5-a]pyridin-8-one (formula I), as described in WO 2002/040484, proceeding from N,N-dimethyl-2-(trialkylsilanyl)imidazole-1-sulphonamide by lithiation and subsequent reaction with a suitably protected 4-hydroxybutyraldehyde, followed by oxidation of the secondary alcohol, acid-induced deprotection of the imidazole and deprotection of the alcohol functionality; 3) a process which proceeds from 5,6,7,8-tetrahydroimidazo[1,5-a]pyridine [38666-30-7], which is oxidized.
6,7-二氢-5H-咪唑[1,5-a]吡啶-8-酮(I)可以通过以下方法高产率地得到:1)从适当保护的C-(3-羟基吡啶-2-基)甲胺开始,其胺基转化为甲酰胺,然后环化为咪唑[1,5-a]吡啶,并氢化为6,7-二氢-5H-咪唑[1,5-a]吡啶-8-酮,适当保护的C-(3-羟基吡啶-2-基)甲胺可以通过两步法从商业可得的3-羟基-2-氰基吡啶[932-35-4]制备,或者通过三步法从商业可得的2-羟甲基吡啶-3-醇[14173-30-9]制备;2)从N,N-二甲基-2-(三烷基硅基)咪唑-1-磺酰胺通过锂化和随后与适当保护的4-羟基丁醛反应,然后氧化二级醇,酸诱导去保护咪唑和去保护醇官能团,制备4-羟基-1-(1H-咪唑-4-基)丁酮,这是合成6,7-二氢-5H-咪唑[1,5-a]吡啶-8-酮(式I)的中间体,如WO 2002/040484中所述;3)从5,6,7,8-四氢咪唑[1,5-a]吡啶[38666-30-7]开始进行氧化的方法。