4-Toluenesulfonyl chloride → HCID 19372765, compound

Participants

Reaction Steps

In THF(640 ml)-DMF(130 ml) was dissolved ethyl 3-(5-methoxy-1H-indol-3-yl)propionic acid (99.3 g, 0.4 mol). To the solution was added in limited amounts, under ice-cooling, a suspension of 60% sodium hydride in oil (18.4 g, 0.46 mol) in THF(50 ml)-DMF(10 ml). The mixture was stirred at room temperature for one hour, and the mixture was again cooled with ice. To the mixture was gradually added p-toluenesulfonyl chloride (83.9 g, 0.44 mmol), followed by stirring for a further 3 hours at room temperature. The reaction mixture was poured into an ice-saturated NH4Cl solution (180 ml). The upper layer was subjected to extraction with ethyl acetate (100 ml+500 ml). The extract solution was washed with a saturated aqueous saline solution (300 ml×2), followed by drying over Na2SO4. The residue was purified by means of silica gel chromatography (eluent: hexane-ethyl acetate (2:1)) and then were added hydrochloric acid (100 ml) and acetic acid (400 ml), and was refluxed for 1 hour. The reaction mixture was concentrated and the resulting crystals were washed with water, dried under reduced pressure and washed with methanol-isopropyl ether (1:3) to obtain the title compound (54.1 g: m.p. 172°-174° C.)

Provenance & Evidence