Ammonia → 1-Naphthalenecarboxylic acid, 1,4-dihydro-2,7-dimethoxy-, methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 2,7-dimethoxy-1-naphthoic acid (I) (0.1 mole) in 150 ml. ether and 600 ml. liquid ammonia was treated with 1.73 g. lithium wire in small portions with stirring under argon. This was allowed to reflux (-33° C.) for 11/2 hours. Ammonium chloride was added to quench the reaction and the ammonia was allowed to evaporate. The residue was taken up in water and washed with ether. The aqueos layer was acidified with 6 N hydrochloric acid and quickly extracted three times with ether. The ether extracts were washed with saturated sodium chloride; and then treated with an ethereal solution of excess diazomethane (prepared from 20.6 g. N-methyl-N-nitrosourea).1After 1/2 hr., acetic acid was added to destroy the excess diazomethane. The solution was washed with dilute sodium carbonate, dried (MgSO4), and concentrated. The residue was crystallized from methanol; mp 90°-91° C.

Provenance & Evidence