摘要:
A process for producing L-tryptophan optionally substituted at the 5-position by a hydroxyl group, which comprises reacting fumaric acid or its salt, an ammonium ion and indole optionally substituted at the 5-position by a hydroxyl group in the presence of (A) fumarase, (B) pyruvic acid-malic acid carboxylase, (C) tryptophanase and (D) NADH oxidase.
摘要:
A process for producing aromatic hydrocarbons in a high yield by introducing a naphtha fraction the cyclopentane content of which is controlled to not more than 1% by weight, or the methylpentane content is controlled to not more than 10% by weight, in a catalytic reaction tower, and contacting with a catalyst comprising a large pore zeolite containing at least one of Group VIII metals of the Periodic Table. In this process, the catalyst cycle is greatly lengthened.
摘要:
A process for preparing indoles in high yield by reacting anilines and 1.2-glycols in a liquid phase in the presence of a cadmium bromide or idoide/potassium bromide or iodide catalyst. The used catalyst can be easily recovered and when reused, exhibits excellent performance.
摘要:
An improved process for preparing a β-acyloxypropionaldehyde by reacting acrolein and a carboxylic acid is disclosed, in which the reaction is in the presence of calcium chloride and/or calcium bromide as a catalyst. The catalyst is very cheap and attains improved conversion and improved selectivity.