3,4-Diaminopyridine → HCID 21779135, compound

Participants

Reaction Steps

A mixture of 3,4-diamino pyridine (10 g) and ethyl pyruvate (53 g) in chloroform (100 mL) was stirred at ambient temperature overnight. The precipitated solid was filtered off, washed with DCM, and dried to afford 2-methyl-4H-pyrido[3,4-b]pyrazin-3-one (14 g) as a yellowish solid. 2 g of this material was suspended in DMF (10 mL) and treated with PyBroP (6 g) and DIPEA (3.3 mL,) at ambient temperature overnight. The precipitated solid was filtered off, washed with ethanol, and dried to afford 3-(benzotriazol-1-yloxy)-2-methyl-pyrido[3,4-b]pyrazine (1.7 g) as a white solid. This material was suspended in ethanol (50 mL), hydrazine hydrate was added, and resulting mixture was heated at 85° C. for 15 min. The solid was filtered off, washed with ethanol, and dried to afford IIc (0.95 g) as a yellow solid sufficiently pure for the next step.

Provenance & Evidence