6490-20-6Relevant articles and documents
PROCESS FOR PRODUCTION OF BETAINE
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Page/Page column 23-24, (2009/09/26)
According to the present invention, by using 4-halogeno-3-hydroxybutanamide as a substrate in quaternary amination reaction with trialkylamine which is an important step in betaine (such as carnitine) preparation processes, it becomes possible to reduce the production of crotonic acid derivatives (the major by-product) greatly compared to conventional processes. Consequently, it becomes possible to prepare a betaine, such as carnitine, at a high yield. The present invention also relates to a process for preparing a betaine represented by formula (1) below, comprising a step of quaternary aminating an amide represented by formula (2) below: wherein A1, A2 and A3 individually represent a C1-C20 hydrocarbon group which may have a substituent(s); and X1 is a halogen atom.
Enantiomeric resolution of a carnitinamide salt by preferential crystallization
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Page/Page column 5-6, (2008/06/13)
A process for the resolution of (D,L)-carnitinamide (D,L-I) chloride in its enantiomers (D-I) and (L-I), characterized in that a supersaturated solution or suspension of (D,L-I) in a suitable solvent or mixture of solvents, optionally added with a surfactant, is used. A series of alternate preferential crystallizations is carried out after adding minimum amount of seeds of one of the two enantiomers, (D-I) or (L-I), that is to be precipitated, and subsequently restoring the supersaturation conditions by adding an appropriate amount of (D,L-I) racemate.