Sulfuric acid magnesium salt (1:1) → 7-(4-chlorobenzoyl)-5-(3-chlorophenyl)-1,5-dihydro-4,1-benzothiazepin-2(3H)-one

Participants

Reaction Steps

A mixture of intermediate (19) (0.079 mol) and MgSO4 (35.5 g) in toluene (500 ml) was stirred and refluxed overnight in a Dean-Stark apparatus and then cooled. The precipitate was filtered off and the filtrate was evaporated till dryness. The residue (35 g) was purified by column chromatography over silica gel (eluent: CH2Cl2/EtOAc 85/15; 20–45 μm). The pure fractions were collected and the solvent was evaporated. The residue was crystallized from acetonitrile and DIPE. The precipitate was filtered off and dried, yielding 1.5 g (4.4%) of 7-(4-chlorobenzoyl)-5-(3-chlorophenyl)-1,5-dihydro-4,1-benzothiazepin-2(3H)-one (intermediate 20), mp. 222° C.

Provenance & Evidence