Patent · US Expired

N-substituted amino acid derivatives

US4535177A · kind A · utility

2Cited by
4References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 14, 1983
Grant dateAug 13, 1985
Priority date
Expiry dateNov 14, 2003

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07D209/20
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

Optical isomeric compounds having the general formula ##STR1## are prepared by: reacting by catalytic hydrogenation a compound of the formula ##STR2## with a compound of the formula ##STR3## wherein R, R.sub.1, R.sub.2 and R.sub.3 are as defined herein, to form a mixture of isomers in a ratio of L(S)L(S)>D(R)L(S); and recovering the (S,S) diastereomer by selectively precipitating an acid salt of the (S,S) ester from the solution.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.