2-(6-Methoxy-2-naphthyl)propionic acid → 4-[2-(6-Methoxynaphthalen-2-yl)propyl]thiomorpholine

Participants

Reaction Conditions

Reaction Steps

Oxalyl chloride (10 ml) is added dropwise to a suspension of 2-(6-methoxynaphth-2-yl)-propionic acid (17.4 g, 75.6 mmols) in benzene (200 ml). After refluxing for 2 hours, the benzene is evaporated off under reduced pressure and the residue is taken up in alcohol-free methylene chloride (100 ml). This solution is added dropwise, in the course of 30 minutes, to a cooled suspension (0° C.) of thiamorpholine hydrochloride (11.6 g, 83.16 mmols) and N-ethylmorpholine (19.12 g, 166 mmols) in methylene chloride (100 ml). After standing overnight, the reaction medium is washed successively with water, hydrochloric acid (10% strength), water, aqueous sodium bicarbonate solution (saturated) and water and then dried (Na2SO4) and evaporated. This yields a solid which is the intermediate (IV). A solution of this amide (5.60 g, 17.78 mmols) in tetrahydrofuran (50 ml) is added dropwise to a stirred solution of borane (55 mmols) in tetrahydrofuran (50 ml), which has been cooled to 0° C. The solution is then heated at the reflux temperature for 2 hours and again cooled to 0° C. Water is then added cautiously in order to destroy the excess borane, and dilute hydrochloric acid is added.

Provenance & Evidence