Sodium Hydroxide → 3,4-Dihydrobenzo[c][1,5]naphthyridin-2(1H)-one

Participants

Reaction Steps

To 300 g of vigorously stirred polyphosphoric acid warmed to 115° C., 10 g of 1,10a-dihydropyrrolo[1,2-b]-isoquinoline-3,10[2H,5H]-dione oxime was added. The mixture was held at this bath temperature for 10 minutes. The internal temperature rose to 135°-140° C. The mixture was then poured into 1500 ml of ice water, and the mixture was basified with 50% NaOH to about pH=8 and the resultant crystalline precipitate was collected to give 7.14 g of crude product. Chromatography on a silica gel column, using ethyl acetate gave 4.8 g of pure product, m.p. 225° C.

Provenance & Evidence