1-Naphthaldehyde → 2-[(Naphthalen-1-yl)methylidene]butanedioic acid

Participants

Reaction Steps

To a solution of 32.3 g of ethyl succinate and 29.0 g of 1-naphthaldehyde in 320 ml of absolute ethyl alcohol was added 10.7 g of a 50% sodium hydride (dispersion in mineral oil) with stirring under ice-cooling, and then the mixture was reflux for 0.5 hours. To the reaction mixture was added 230 ml of a 1N-aqueous sodium hydroxide solution, and the mixture was reflux for 1 hour. The reaction mixture was concentrated under reduced pressure, and water was added to the residue. The mixture was extracted with diethyl ether to remove neutral substances. An aqueous layer was acidified by the addition of concentrated hydrochloric acid, and the acid solution was extracted with diethyl ether. The ethereal layer was washed with a saturated sodium chloride aqueous solution, dried over magnesium sulfate and concentrated under reduced pressure. Benzene was added to the residue, and precipitated crystals were collected by filtration to obtain 26.5 g of 2-(1-naphthylmethylene)succinic acid as yellow crystals.

Provenance & Evidence