Indole derivatives

Benzylthio(skatyl)malonic ester has been synthesized by the condensation of gramine in toluene or its methiodide in ethanol with benzylthiomalonic ester, and this has been converted by monodecarboxylation and debenzylation with sodium in liquid ammonia into DL--mercapto--(indol-3-yl)propionic acid [-(3-indol-yl) thiolactic acid]. DL--Benzylmercapto--(indol-3-yl)propionic acid has also been obtained from methyl DL--bromo--(indol-3-yl)propionate and benzyl mercaptan. Alkaline hydrolysis of S-[-(indol-3-yl)--methoxycarbonylmethyl]thiouronium bromide has led to ring closure with the formation of 5-skatylthiazolidine-2, 4-dione.For part XLVIII, see [1].