Lawesson's reagent → 1,3-Dihydro-5-cyclohexyl-3(R,S)-[(benzyloxycarbonyl)-amino]-2H-1,4-benzodiazepin-2-thione

Participants

Reaction Steps

1,3-Dihydro-5-cyclohexyl-3(R,S)-[(benzyloxycarbonyl)-amino]-2H-1,4-benzodiazepin-2-one (M. Chambers, et. al. Biomed. Chem. Lett. 1993, in press) (1.09 g, 2.79 mmole) was mixed with 1.13 g (2.79 mmole) of 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide in 26 ml of toluene. The resulting suspension was heated to reflux for 1 hour. The reaction mixture was cooled, filtered, and concentrated in vacuo. The residue was flash chromatographed on silica gel (ethyl acetate-hexane, 1:3) and the product containing fractions were pooled and concentrated to give the title compound in approximately 85% purity. This material was recrystallized from hexane-ethyl acetate (1:1) to give 850 mg (75%) of the title compound in analytical form: m.p. 164°-165° C.

Provenance & Evidence