Methanethiol → 7-(Methylthio)-1,8-naphthyridin-2-amine

Participants

Reaction Conditions

Reaction Steps

To a solution, close to saturation, of methyl mercaptan in dimethylformamide (200 cc) maintained at 0° C., sodium hydride (13.3 g) in 50% strength suspension in mineral oil is added in small portions. 2-Amino-7-chloro-1,8-naphthyridine (25 g) is then added to this solution, and the mixture is heated at 100° C. for 2 hours. After being cooled, the reaction mixture is poured into water (500 cc) and extracted with methylene chloride (5×250 cc). The organic extracts are then washed with distilled water (2×200 cc), dried over magnesium sulphate and concentrated to dryness at 40° C. under reduced pressure (4 kPa). The product produced (22.9 g; m.p. 130° C.) is dissolved in boiling ethanol (150 cc). After 2 hours' cooling at 4° C., the crystallised solid is separated by filtration, washed with ethanol (10 cc) and then isopropyl ether (3×10 cc), and dried at 40° C. under reduced pressure (0.067 kPa). 2-Amino-7-methylthio-1,8-naphthyridine (9.6 g) is produced, m.p. 158° C.

Provenance & Evidence