2,3-Diaminopyridine → HCID 69280097, compound

Participants

Reaction Conditions

Reaction Steps

Polyphosphoric acid (PPA) (10 g) was heated to 160° C. Intermediate (1) (0.0467 mol) and 2,3-diaminopyridine (0.0513 mol) were added. The mixture was stirred at 180° C. for 1 hour, poured out on K2CO3 solid and ice, washed with K2CO3 10% and extracted with DCM. The aqueous layer was washed with DCM. The organic layer was dried, filtered and the solvent was evaporated.This fraction was purified by column chromatography over silica gel (eluent: CH2Cl2/CH3OH/NH4OH 94/6/0.5). The pure fractions were collected and the solvent was evaporated. Part of this fraction (6 g) was crystallized from DIPE and 2-propanone. The precipitate was filtered off and dried, yielding 3.16 g of (±)-2-[hexahydro-1-(phenylmethyl)-1H-azepin-4-yl]-1H-imidazo[4,5-b]pyridine (compound 69).

Provenance & Evidence