Patent IE-56654-B1 (IE)
Title: A process for the resolution of racemates of optically active bicyclic imino-alpha-carboxylic esters,and the use of the compounds thus obtainable for the synthesis of carboxyalkyldipeptides
IPC: C07B57/00
Filed: 1984-01-30
Abstract: For the Contracting States BE CH DE FR GB IT LI LU NL SE 1. A process for resolving racemic mixtures of bicyclic imino-alpha-carboxylic esters into the components of the formula Ia and Ib see diagramm : EP0115345,P15,F1 in which R represents an aliphatic radical having 1 to 6 carbon atoms, an alicyclic radical having 4 to 10 carbon atoms, an aromatic radical having 6 to 12 carbon atoms or an araliphatic radical having 7 to 15 carbon atoms, a) A and B**1 denote hydrogen, and B**2 and C together form a chain of the formula -[CH2 ]n -, with n being 3, 4, 5 or 6, or a chain of the formula -[CH2 ]p -CH=CH-[CH2 ]q -, with (p+q) being 1, 2, 3 or 4, b) C and B**2 denote hydrogen, and A and B**1 together form a chain of the formula -[CH2 ]n -, with n bein 3, 4, 5 or 6, or a chain of the formula -[CH2 ]p -CH=CH-[CH2 ]q -, with (p+q) being 1, 2, 3 or 4, or c) A and C denote hydrogen, and B**1 and B**2 together form a chain of the formula -[CH2 ]m -, with m being 4, 5, 6 or 7, by crystallization of diastereomeric salts, which process comprises preparing the salts of the racemic esters with optically active N-acylated R- or S-aminocarboxylic acids which contain a phenyl nucleus, from the series phenylalanine, phenylglycine, beta-phenyl-alpha-aminobutyric acid, 3,4-dihydroxyphenylalalin, beta-phenylserine and tyrosine, recrystallizing them form an aprotic organic solvent or an alcohol having up to 6 carbon atoms, decomposing the precipitated, optically homogenous diastereomeric salts in a manner known per se, and isolating the enantiomers of the formula Ia or Ib, respectively, and where appropriate, converting the latter into the free acids by saponification or hydrogenolysis in a manner known per se. For the Contracting State AT 1. A process for resolving racemic mixtures of bicyclic imino-alpha-carboxylic esters into the components of the formula Ia and Ib see diagramm : EP0115345,P17,F1 in which R represents an aliphatic radical having 1 to 6 carbon atoms, an alicyclic radical having 4 to 10 carbon atoms, an aromatic radical having 6 to 12 carbon atoms or an araliphatic radical having 7 to 15 carbon atoms, a) A and B**1 denote hydrogen, and B**2 and C together form a chain of the formula -[CH2 ]n -, with n being 3, 4, 5 or 6, or a chain of the formula -[CH2 ]p -CH=CH-[CH2 ]q -, with (p+q) being 1, 2, 3 or 4, b) C and B**2 denote hydrogen, and A and B**1 together form a chain of the formula -[CH2 ]n -, with n being 3, 4, 5 or 6, or a chain of the formula -[CH2 ]p -CH=CH-[CH2 ]q -, with (p+q) being 1, 2, 3 or 4, or c) A and C denote hydrogen, and B**1 and B**2 together form a chain of the formula -[CH2 ]m -, with m being 4, 5, 6 or 7, by crystallization of diastereomeric salts, which process comprises preparing the salts of the racemic esters with optically active N-acylated R- or S-aminocarboxylic acids which contain a phenyl nucleus, from the series phenylalanine, phenylglycine, beta-phenyl-alpha-aminobutyric acid, 3,4-dihydroxyphenylalanin, beta-phenylserine and tyrosine, recrystallizing them form an aprotic organic solvent or an alcohol having up to 6 carbon atoms, decomposing the precipitated, optically homogenous diastereomeric salts in a manner known per se, and isolating the enantiomers of the formulae Ia or Ib, respectively, and, where appropriate, converting the latter into the free acids by saponification or hydrogenolysis in a manner known per se.