Acetic Anhydride → 5-[2-(Dimethylamino)ethyl]-2-(4-methoxyphenyl)-4-oxo-2,3,4,5-tetrahydronaphtho[1,2-b][1,4]thiazepin-3-yl acetate

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Reaction Steps

A mixture of 3.0 g (-)-cis-2,3-dihydro-3-hydroxy-2-(4-methoxyphenyl)-5-[2-(dimethylamino)ethyl]naphtho[1,2-b]-1,4-thiazepin-4(5H)-one hydrochloride and 5 mL of acetic anhydride was stirred at 100° for 17 hours. The excess reagent was removed under reduced pressure and to the residue, ice-water was added. The resulting suspension was made basic with concentrated ammonium hydroxide and extracted with methylene chloride. The combined extracts were washed with water (10 mL) and dried (magnesium sulfate). Removal of the solvent under reduced pressure gave 2.5 g (83%) of (-)-cis-3-(acetyloxy)-2,3-dihydro-2-(4-methoxyphenyl)-5-[2-(dimethylamino)ethyl]naphtho[1,2-b]-1,4-thiazepin-4(5H)-one as an amorphous substance, [α]D25 -10.1° (C 0.57, MeOH).

Provenance & Evidence