(3aR*,10aS*)-9-[4-(benzyloxycarbonylamino)benzyl]-4-(phthalimidoacetyl)-2,3,3a,4,9,10a-hexahydrobenzo[b]cyclopenta[e][1,4]diazepin-10(1H)-one → (3aR*,10aS*)-9-(4-Aminobenzyl)-4-(phthalimidoacetyl)-2,3,3a,4,9,10a-hexahydrobenzo[b]cyclopenta[e]-[1,4]diazepin-10(1H)-one hydrobromide

Participants

Reaction Steps

To a solution of (3aR*,10aS*)-9-[4-(benzyloxycarbonylamino)benzyl]-4-(phthalimidoacetyl)-2,3,3a,4,9,10a-hexahydrobenzo[b]cyclopenta[e][1,4]diazepin-10(1H)-one (5.15 g, 8.2 mmol) in chloroform (80 mL) was added 25% hydrogen bromide/acetic acid (15 mL) and the mixture was stirred at room temperature for 45 minutes. This reaction mixture was concentrated under reduced pressure and the residue was crystallized from ethanol-diethyl ether to provide (3aR*,10aS*)-9-(4-aminobenzyl)-4-(phthalimidoacetyl)-2,3,3a,4,9,10a-hexahydrobenzo[b]cyclopenta[e][l,4]diazepin-10(1H)-one hydrobromide. This product was suspended in chloroform and treated with 0.5N-aqueous NaOH solution (40 mL). The aqueous layer was separated and the organic layer was washed with water, dried over MgSO4, filtered, and concentrated under reduced pressure. The residue was crystallized from chloroform-diethyl ether to provide 3.71 g (yield 91%) of the title compound. m.p. 286°-289° C.

Provenance & Evidence