Hydrochloric Acid → HCID 24839540, compound

Participants

Reaction Steps

2-(n-Undecyl)indole-5-carboxylic acid (45 g) was added to a mixture of tetrahydrofuran (250 ml), glacial acetic acid (50 ml) and perchloric acid (25 ml of strength 70% w/v). The mixture was hydrogenated over palladium on charcoal (5% w/w, 5 g) at room temperature and atmospheric pressure. When hydrogen uptake had ceased (after 6 hours), the mixture was filtered through diatomaceous earth, and the residue was washed with tetrahydrofuran (2×50 ml). The combined filtrates were adjusted to pH 4 by treatment with an aqueous solution of sodium hydroxide (strength 50% w/v). The mixture was diluted with water (200 ml) and was extracted with diethyl ether (3×200 ml). The diethyl ether solution was dried over magnesium sulphate and, on evaporation in vacuo gave a solid. The solid was dissolved in diethyl ether (100 ml) and the solution was treated with an excess of a solution of hydrogen chloride in ethanol (strength 38% w/v, 30 ml). The mixture was diluted with diethyl ether (1000 ml) and a solid was collected. The solid was recrystallised from isopropanol to give (RS)-2-(n-undecyl)-indoline-5-carboxylic acid hydrochloride (27.6 g), in the form of a white solid m.p. 175°-179° C. (with decomposition).

Provenance & Evidence