Diethyl Malonate → 7-Amino-4-hydroxy-1,8-naphthyridin-2(1H)-one

Participants

Reaction Steps

The procedure used was a modification of that by Lappin et al. [G. A. Lappin, Q. R. Petersen and C. E. Wheeler, J. Org. Chem. 15, 377 (1950)]. 2,6-Diaminopyridine (10.9 g, 0.1 mole) and 16.0 g (0.1 mole) of diethyl malonate in 250 ml of diphenyl ether were heated with stirring under an air condenser at 170°-180° for 1 hr. Then the temperature was slowly increased to 245°. The total heating time from room temperature to final temperature was 4.5 hr. Off-white solid began to separate soon after 180° was reached. The slurry was cooled, diluted with 100 ml of benzene, filtered, and the solid product washed several times with benzene; 17.7 g (100%) after drying. The experiment was also readily performed on a 0.4-mole scale.

Provenance & Evidence