| 摘要 |
PCT No. PCT/EP94/04259 Sec. 371 Date Jun. 5, 1996 Sec. 102(e) Date Jun. 5, 1996 PCT Filed Dec. 21, 1994 PCT Pub. No. WO95/18093 PCT Pub. Date Jul. 6, 1995Process for the preparation of an N-substituted glycine ester or an N-substituted glycine acid by reaction of a glyoxylic acid ester half-acetal (hemiacetal) or glyoxylic acid half-acetal (hemiacetal) with an amine and hydrogenation of the intermediate product formed by this reaction, and the use of the process in a process for the preparation of indoxyl and indigo derivatives by cyclization of an N-arylglycine ester, prepared by the above process, in a molten alkali metal carbonate or alkaline earth metal carbonate with or without addition of an alkali metal amide, and if appropriate oxidation of the indoxyl derivative formed by this reaction to give the corresponding indigo derivative. |
