30193-56-7Relevant articles and documents
Preparation and purification method of diltiazem chiral isomer impurity
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, (2019/11/20)
The invention provides a method for preparing and purifying a diltiazem chiral isomer. The method comprises the steps of taking p-methoxybenzaldehyde as a starting raw material, carrying out Darzens condensation, a reaction with o-aminobenzenethiol and a cyclization reaction to prepare an intermediate, carrying out chiral column separation on the intermediate, then carrying out an alkylation and acetylation reaction separately to obtain a diltiazem chiral isomer impurity I. The method is simple to operate and short in period, and the purity of the obtained diltiazem chiral isomer impurity is high, so that a reference substance is provided for quality research and drug synthesis process research of diltiazem drugs, and the method has important significance in control and checking of the chiral purity in the pharmaceutical research of diltiazem.
Process for the recycle of a waste product of diltiazem synthesis
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, (2008/06/13)
A process which allows the re-use of compounds of formula in diltiazem synthesis through a process of conversion to a mixture of enantiomers III-(2R,3R) and III-(2S,3S) is described.
Optical resolution of a 1,5-benzothiazepine derivative, a synthetic intermediate of diltiazem, by preferential crystallization and diastereomeric salt formation
Yamada, Shin-Ichi,Yoshioka, Ryuzo,Shibatani, Takeji
, p. 1922 - 1927 (2007/10/03)
Practical preparation methods of an optically active intermediate of diltiazem, (+)-(2S,3S)-5-[2-(dimethylamino)ethyl]-2,3-dihydro-3-hydroxy-2- (4-methoxyphenyl)-1,5-benzothiazepin-4(5H)-one [(+)-7], have been developed by the use of physicochemical and chemical resolutions. 1) The salt of (+)-7 with 3-amino-4-hydroxy-benzenesulfonic acid (AHS), was found to exist as a conglomerate and could be reproducibly resolved into (+)-7·AHS and (-)- 7·AHS of 94-98% ee by a preferential crystallization procedure. 2) (+)- (1R)-3-Bromocamphor-9-sulfonic acid [(+)-BCS] was found to be an efficient resolving agent for (±)-7 and the diastereomeric resolution provided (+)- 7·(+)-BCS·2H2O salt in >43% yield and >97% ee by fractional crystallization. It is presumed that the crystal water of (+)-7·(+)- BCS·2H2O plays an important role in the selective crystallization during this efficient resolution.