Benzoic acid, 2-mercapto-, methyl ester → (+/-)-3-Butyl-3-ethyl-2,3-dihydro-1,4-benzothiazepin-5(4H)-one

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Reaction Steps

To a solution of methyl thiosalicylate (25.0 g, Aldrich) in methanol (95 ml) at 0° C. was added 2-butyl-2-ethylaziridine (20.0 g, Synthetic Example 1(f)) and the mixture was stirred at room temperature for 18 hours. Solvent was evaporated and toluene (200 ml) and sodium methoxide (8.2 g) were added. The mixture was heated to reflux for 4.5 hours, removing water through a Dean-Stark trap. Solvent was evaporated and the residue was partitioned between 5% HCl (500 ml) and dichloromethane (400 ml). The organic layer was separated, dried and concentrated. Crystallization from hexanes/ethyl acetate provided the title compound as a white solid (38.0 g), mp 92°-93° C. 1H NMR consistent with the proposed structure.

Provenance & Evidence