p-Toluenesulfonic acid → HCID 15203933, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 2,3-dihydro-7,8-dimethyl-4-[4-(2-methylimidazo[4,5-c]pyrid-1-yl)phenyl]-1H-[1,5]benzodiazepin-2-thione (575 mg. 1.4 mmol), aminoacetaldehyde dimethyl acetal (294 mg, 2.8 mmol), and p-toluenesulphonic acid (14 mg) in n-butanol (7 ml) was heated at reflux for 8 hours under nitrogen. The solvent was removed under reduced pressure, and the residue was purified by flash chromatography (eluting with ethyl acetate/methanol=6:1). The intermediate thus obtained was dissolved in concentrated sulphuric acid (5 ml) and heated at 100° C. for 20 minutes. The mixture was cooled and poured onto ice, and then neutralised with saturated aqueous sodium bicarbonate. The product was extracted into dichloromethane (2×150 ml), and the combined extracts were dried (MgSO4) and concentrated under reduced pressure. Purification by flash chromatography (eluting with ethyl acetate:methanol=6:1) gave the title compound as a buff solid, (180 mg, 31%), m.p. 193°-195° C. after dissolution in methanol and precipitation with acetone.

Provenance & Evidence