Sodium Hydroxide → 8-Dimethylamino-2,7,8,9-tetrahydro-6-oxa-2-azabenzo[cd]azulene-5-carboxylic acid amide

Participants

Reaction Conditions

Reaction Steps

Polyphophoric acid 420 mg was added to compound (48) 31.6 mg under an argon atmosphere and the mixture was heated at 90° C. for 6 h. Ice-water was added to the reaction mixture, which was made alkaline with an aqueous 5 N-sodium hydroxide solution and extracted with chloroform. The extracts were washed with brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue obtained was chromatographed on aluminum oxide in chloroform:methanol (97:3) to give the titled compound as colorless crystals, 20.9 mg. Yield 62%. Furthermore, the titled compound was recrystallized from acetone-isopropyl ether to give colorless crystals, m.p. 182-183° C.

Provenance & Evidence