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 Δ3‐thiazolines, Δ3‐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 Δ3‐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.