Ethyl orthoformate → 2,3,5,6,7,8-Hexahydro-1'-methyl-5-(2'-methyl-4'-(1,3,4-oxadiazol-2-yl)biphenyl-4-carbonyl)spiro[furo[2,3-g]quinoline-3,4'-piperidine]

Participants

Reaction Steps

A suspension of 2,3,5,6,7,8-hexahydro-1'-methyl-5-(4'-hydrazinocarbonyl-2'-methylbiphenyl-4-carbonyl)spiro[furo[2,3-g]quinoline-3,4'-piperidine] (E49) (794 mg) in triethylorthoformate (25 ml) was heated at reflux overnight. The mixture was concentrated in vacuo and the residue refluxed overnight in xylene (40 ml) to complete cyclisation. The xylene was evaporated under reduced pressure and the residue purified by chromatography on silica gel, eluting with chloroform and methanol, to afford the title compound (470 mg, 58%). The hydrochloride salt precipitated from acetone as a white solid.

Provenance & Evidence