4-Chlorobenzaldehyde → HCID 20242542, compound

Participants

Reaction Conditions

Reaction Steps

A flask containing polyphosphoric ester (90 g) was held at 100° C. (oil bath temperature). A mixture of 3,4-methylenedioxyphenylacetamide (22 g, 123 mmol) and parachlorobenzaldehyde (17.1 g, 122 mmol) was added in three portions over half an hour, with stirring. The solution (dark red) was heated at 100° C. for 5 h and poured onto ice (400 ml). A 10% solution (aqueous) of sodium carbonate (2 liters) was added and the mixture was left overnight. The resulting oily gum was extracted with chloroform (2×500 ml) and the chloroform extracts washed with brine (50 ml) and dried over sodium sulphate. The chloroform solution was filtered and the solvent was removed under reduced pressure. The solid so formed was triturated with ethanol (2×30 ml) to give 1-(4-chlorophenyl)-6,7-methylenedioxy-1,4-dihydroisoquinol-3-one (7 g). The combined ethanol layers were evaporated under reduced pressure and the residue chromatographed (Silica gel (300 g), chloroform as eluent) to give a further 8 g of product. Total yield (15 g, 41%), m.p. 200°-202° C. (ethanol).

Provenance & Evidence