Sulfuric Acid → 6,7-Dimethoxy-1-oxo-1,2-dihydroisoquinoline-4-carbonitrile

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of [2-cyano-2-(3,4-dimethoxy-phenyl)-vinyl]-carbamic acid ethyl ester (8 g, 29.0 mmol) in diphenyl ether (70 mL) was added concentrated sulfuric acid (0.5 mL). The reaction mixture was heated at 230° C. for 4 hrs, cooled and diluted with diethyl ether (400 mL). A brown solid was precipitated, filtered, collected and washed with diethyl ether to afford 6,7-dimethoxy-1-oxo-1,2-dihydro-isoquinoline-4-carbonitrile. (3.5 g, 52% yield).

Provenance & Evidence