Sodium Hydroxide → HCID 22914799, compound

Participants

Reaction Steps

The product of Step B hereof (31.5 g, 139 mmol) is cyclized in polyphosphoric acid (1.24 kg) at 200° C. for 51/2 hours. The hot reaction is poured into ice and then basified with 50% NaOH solution. The product is extracted three times with CHCl3 and then washed with brine. The organic phase is dried (Na2SO4), filtered, and solvent is removed to give the desired product (20.4 g) in 64% yield, m.p. 78°-81° C. after recrystallization from diisopropyl ether.

Provenance & Evidence