Ethyl pyruvate → 3,6-Dimethyl-3,4-dihydropyrido[2,3-b]pyrazin-2(1H)-one

Participants

Reaction Steps

2,3-Diamino-6-methylpyridine (3.0 g, 0.024 mol) and 3.2 ml (0.028 mol) of ethyl pyruvate were heated under reflux in 100 ml of 1,2-dimethoxyethane for 4 h. The resulting precipitate (3.9 g) of 3,6-dimethyl-1,4,5-triazanaphthalen-2(1H)-one was filtered off with suction, dried and used directly for the hydrogenation. A reaction analogous to that described for Example 1 resulted in 2.27 g (58%) of the desired compound of melting point 203°-205° C.

Provenance & Evidence