Loading patent…
AssigneeHaarmann & Reimer GmbH
InventorsJurgen Fleischer, Kurt Bauer, Ruldolf Hopp
Estimating the term…
A process for the separation of optically active d- and l-isomers of a compound selected from the group consisting of menthol, neomenthol and isomenthol, which comprises esterifying a d,l-isomeric mixture of the compound with an acid selected from the group consisting of benzoic acid optionally carrying at least one substituent on the benzene ring and hexahydrobenzoic acid; forming a supersaturated solution or a supercooled melt of the d,l-ester; inoculating the solution or melt with crystals of the d- or l-form of the ester to effect selective crystllization of one of the two optical isomers; separating the crystals and subjecting them to hydrolysis to yield the corresponding enantiomorph of the starting compound.
A process for the separation of optically active d- and l-isomers of a compound selected from the group consisting of menthol, neomenthol and isomenthol, which comprises forming a super-saturated solution or a supercooled melt consisting essentially of a d,l-isomeric mixture of an ester of the compound with an acid selected from the group consisting of benzoic acid, hexahydrobenzoic acid and benzoic acid substituted by up to 2 lower alkyl or alkoxy, fluorine, chlorine, bromine or nitro groups inoculating the solution or melt with crystals of the d- or l-form of the ester to effect selective crystallization of one of the two optical isomers;
Dependencies are inferred from the claim text.