F.i.s. Fabbrica Italiana Sintetici S.p.a.

Zamon Group S.p.a.

Zach System S.p.a.

Gaetano Marchioro

Pietro Allegrini

Marco Villa

Giuseppe Barreca

Vincenzo Cannata

Andrea Nicoli

Laura Russo

Francesco Corcella

Katiuscia Arrighi

Amleto Rizzi

A process which allows the re-use of compounds of formula ##STR1## in diltiazem synthesis through a process of conversion to a mixture of enantiomers III-(2R,3R) and III-(2S,3S) is described.

Process for the recycle of a waste product of diltiazem synthesis

The present invention relates to a process for the separation of the enantiomers of threo-2-hydroxy-3-(2'- aminophenylthio)-3-(4'-methoxyphenyl)-propionic acid, which is an important intermediate in the synthesis of pharmacologically active compounds, by means of the direct crystallization of the relevant cyclohexylaminic salt. According to a preferred form of practical embodiment of the present invention, the optically pure acid is recovered as the hydrochloride of the corresponding methyl ester.

Process for the optical resolution of

The present invention relates to a novel process for synthetizing 2-aryl-3-hydroxy-cis-2,3-dihydro-1,5-benzothiazepin-4(5H)-ones and their derivatives, an optically pure compounds or as their racemic mixtures, having the following general formula (I): ##STR1## by using, as synthesis precursors, methyl esters of 2-hydroxy-3-arylthio-3-arylpropionic acids in their threo form, as their hydrochlorides, or as free bases, of generally formula (II): ##STR2## and treating such precursors with an excess of sodium methoxide, at low temperature, in diethyleneglycol, dimethylether, diemthylformamide and ethyl acetate.

Process for preparing

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Vicenza, Italy

Gaetano Marchioro