Syntheses with ketones, sulfur, and ammonia or amines at room temperature

A large number of preparatively interesting compounds have become readily available by the simultaneous action of sulfur and ammonia or amines on ketones. Direct syntheses of Δ 3 ‐thiazolines, Δ 3 ‐imidazoline‐5‐thiones, 5,6‐dihydro‐4H‐1,4‐thiazines, and the 1,2,3,4,5,6‐hexathiocane system from ketones, sulfur, and ammonia or amines, and further possibilities for the synthesis of these heterocyclic systems have been proposed. Other heterocycles containing N or N and S (thiazoles, thiophenes, thiazolidines, tetrahydrothiazolo[2,3‐c]‐1,4‐thiazines, thiomorpholines, 4‐amino‐2H‐imidazoles, etc.) are readily obtainable by further reactions of these compounds. Hydrolysis of the Δ 3 ‐thiazolines yields α‐mercapto ketones, which are the starting materials for other syntheses. Most of the syntheses described proceed at room temperature and at normal pressure.