Studies on Thiazoles. I. 4-Methylthiazole-5-acetic Acid and Some of its Derivatives

Abstract

Studies on Thiazoles. I. 4-Methylthiazole-S-acetic Acid and Some of its Deriva-

Neuere Methoden der präparativen organischen Chemie IV Synthesen von Thiocarbonsäureamiden

“…Der Thiocarbonsaurearn~d Im allgemeinen wird die Estergruppe nicht angegriffen, wie die Schwefelung der Athoxycarbonylthioformamide (62) und (63) zeigt [81,851. Eine interessante Ausnahme von dieser Regel beobachtete Legrand 1861 bei der Schwefelung von N-Acetylanthranilsaure-methylester (70), der sowohl an der Amid-als auch an der Estergruppe geschwefelt wird und dann zum 2-Methyl-4H-3,lbenzothiazin-4-thion (71) …”

Steroids IX

“…We prepared the a-halo carbonyl compound, 2aol-bromo-5a-cholestan-3-one (11) according to the method of Fieser and Dominguez (5). This procedure entails the bromination of 5a-cholestan-:&one (I) in glacial acetic acid in the presence of hydrobrotnic acid to give 2a-bromo-5a-cholestan-:bone (11) in a 14yo yield.…”

“…This procedure entails the bromination of 5a-cholestan-:&one (I) in glacial acetic acid in the presence of hydrobrotnic acid to give 2a-bromo-5a-cholestan-:bone (11) in a 14yo yield. The carbonyl group of the brominated ketone absorbs a t 5 .…”

“…The method recommended by Cerecedo and Tolpin (11) for the synthesis of thioformamide was then tried. The crude thioformamide was prepared by the addition of phosphorus pentasulfide to formamide which have been covered with anhydrous ether.…”

“…The ether layer was separated and evaporated a t reduced temperature and pressure to yield the crude thioformamide. The thioformamide was added in generous excess to a solution of 2a-bromo-5~-cholestan-3-one (11) in a mixture of chloroform and ethanol. The reaction mixture was stored in the refrigerator for 4 days and allowed to stand a t room temperature for 2 weeks.…”