2-Aminothiazole → HCID 21537677, compound

Participants

Reaction Steps

15.75 g. of 6-ethoxy-1-ethyl-3-methyl-1H-pyrazolo[3,4-b]-pyrazine-5-carbonyl chloride (0.058 mol.) are dissolved in 150 ml. of dry toluene. To this well cooled solution (ice/sodium chloride) a solution of 6.4 g. of 2-aminothiazole (0.638 mol.) and 6.5 g. of triethylamine (0.638 mol.) in 260 ml. of dry toluene is added dropwise under stirring. The reaction temperature is kept at -5° to -10°. Then stirring is continued at room temperature for 1 hour and at 50° for 1 hour. The precipitated triethylamine hydrochloride is filtered off and the toluene filtrate is removed in vacuo. Recrystallization of the residual 6-ethoxy-1-ethyl-3-methyl-N-2-thiazolyl-1H-pyrazolo[3,4-b]pyrazine-5-carboxamide gives 15.4 g. of product (78%), m.p. 158°-159°.

Provenance & Evidence