Hydrochloric Acid → 7-Methoxyisoquinoline

Participants

Reaction Conditions

Reaction Steps

Aminoacetaldehyde dimethyl acetal (81.9 mL) was added to a solution of 60.8 mL of 3-methoxy-benzaldehyde in 600 mL of toluene. The mixture was refluxed for 5 h using a Dean-Stark trap and subsequently cooled to 5° C. In a nitrogene atmosphere trifluoroacetic acid anhydride (209 mL) and borontrifluoride etherate (185 mL) were added in succession at such a rate, that the internal temperature was kept below 10° C. After stirring for 3 days at room temperature the the reaction mixture was poured on ice, 250 mL 2 N hydrochloric acid added and the organic layer extracted with 1 N hydrochloric acid. The pH value of the combined aqueous extracts was adjusted to pH 9 by adding concentrated aqueous ammonia. Extraction with ethyl acetate, followed by drying and removal of the solvent in vacuo gave 66.9 g (84%) of the title compound as a light brownish oil. EI-MS: 159 (M+).

Provenance & Evidence