Formic Acid → HCID 90420169, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of the above prepared 6-bromo-2-ethyl-8-methyl-imidazo[1,2-a]pyridin-3-ylamine hydrochloride (785 g, 2.70 mol, 1 eq.) in formic acid (713 mL, 18.9 mol, 7 eq.) was heated to 80° C. for 2 h. The crude mixture was concentrated in vacuo to low volume (about 400 mL). The residue was brought up in water (1 L) and a 3 M solution of NaOH (2 L), and further basified with a saturated NaHCO3 solution until foaming ceased and pH reached 8-9. After homogenization for 1 h, the precipitate was filtered and washed with water (2×300 mL). Purification was achieved by dissolution in a mixture of toluene and MeOH 3:1 (4 L) followed by concentration in vacuo. Trituration of the residue in a mixture of 200 mL of MeOH and 5 L of DIPE, decantation and filtration of the resulting suspension afforded N-(6-bromo-2-ethyl-8-methylimidazo[1,2-a]pyridin-3-yl)formamide (Intermediate Gen-2-d).

Provenance & Evidence