3,5-二甲氧苯基己基酮的合成

Synthesis of 1-(3,5-Dimethoxyphenyl)-1-heptanone

以3,5-二甲氧基苯甲酰胺为原料,经氰化反应,格式反应合成大麻隆的重要中间体-3,5-二甲氧苯基己基酮。较佳的合成工艺条件为:(1)腈基化反应:以0.2 mol 3,5-二甲氧基苯甲酰胺为基准,滴加时间2 h,质量分数(NaOH)=50%,溶剂为氯仿,相转移催化剂为TEBA,反应收率为74.39%;(2)格式反应:以0.25 mol 3,5-二甲氧基苯甲腈为基准,正溴己烷格氏试剂四氢呋喃溶液与3,5-二甲氧基苯甲腈的摩尔比为1.5∶1,回流时间为12 h,反应收率为92.1%。两步反应总收率为68.5%。通过熔点,沸点,1H NMR确证目标产物的化学结构。

1-（3,5-Dimethoxyphenyl）-1-heptanone,an important intermediate for preparation of nabilone,was synthesized to form 3,5-Dimethoxybenzamide by cyanidation reaction and Grignard reaction.The better synthesis process conditions were that in cyanidation reaction： 0.2 moL 3,5-Dimethoxybenzamide as bench marks,adding time 2 h,w（NaOH）=50%,the solvent for chloroform,phase transfer catalyst for TEBA,the yield of 3,5-Dimethoxybenzamide was 74.39%,and in Grignard reaction： 0.25 moL 3,5-Dimethoxybenzonitrile as benchmark,Grignard reagent and 3,5-Dimethoxybenzonitrile molar ratio of 1.5：1,the backflow time for 12 h,the yield was 3,5-Dimethoxybenzonitrile was 92.1%.Two step total yield of 68.5%.The structures of the target product were confirmed by means of the boiling point and 1H NMR.