环保法规推动新的更安全,毒性较低的生物基溶剂的查找替换争议的高沸点溶剂,如ñ甲基-2-吡咯烷酮和ñ,ñ在化工行业二甲基甲酰胺。最近,N-烷基-2-吡咯烷酮和5-甲基-N-烷基-2-吡咯烷酮被提议作为许多应用的有吸引力的替代溶剂。在这里,我们报告了一种基于生物的两步化学催化系统,该系统可以从谷氨酸和C 3 -C 5羰基化合物开始合成范围广泛的N-烷基-2-吡咯烷酮。第一步N通过温和且有效的Pd催化的还原性N-烷基化以高产率(> 85%)合成了谷氨酸的α-单烷基化衍生物。随后,在惰性气氛下在250℃下热诱导内酰胺化成相应的N-烷基焦谷氨酸,然后Pd催化脱羧,得到N-烷基-2-吡咯烷酮。通过用碱中和N-烷基焦谷氨酸底物,部分抵消了水解降解,导致产率高达82%。最后,两个反应步骤在相同的Pd / Al 2 O 3催化剂下,在不同的气体气氛和温度条件下,通过一锅法成功地结合在一起。
Manufacturing process for N-carbobenzyloxy-L-glutamic acid-alpha-cholinester salt
申请人:MORINAGA MILK INDUSTRY CO., LTD.
公开号:EP0135351A1
公开(公告)日:1985-03-27
The invention relates to manufacturing process for a halide or an organic sulfonate of N-carbobenzyl-L-glutamic acid-a-cholinester in high purification, which is useful as e.g. hypotensive drug. According to the prior art, undesired γ-form byproduct is inevitably formed to be mingled with said a-form objective compound of which separation is difficult. It has been found that when using N-carbobenzyloxy-γ-tert. butyl-L-glutamic acid-dicyclohexyl-ammonium salt readily available in high purification as starting material, reacting N, N-dimethyl-aminoethylchloride therewith to form N-carbobenzyloxy-γ-tert. butyl-L-glutamic acid-a-dimethylaminoethyl ester which is quarternerized to form N-carbobenzyloxy-γ-tert. butyl-L-glutamic acid- α-cholinester salt, which is subjected to mild salt treatment, the objective compound can be obtained in high purification.
A composition suitable for topical application to mammalian skin and hair for inducing, maintaining or increasing hair growth comprises a hair growth promoter chosen from glutamic acid derivatives and salts thereof. The composition preferably also comprises an activity enhancer which may be chosen from hair growth stimulants, penetration enhancers and cationic polymers.