Abstract Propionaldehyde, n-butyraldehyde and n-valeraldehyde react with ethylenimine in the presence of dimethylformamide or anhydrous K 2 CO 3 to mixtures of 2-monoalkylated 5.6-dihydro-4 H-1.4-thiazines (2–4) and 2-monoalkylated thiazolidines (6–8). When acetaldehyde is inserted in this reaction, solely 2-methyl-thiazolidine (5) could be isolated. By condensation of α-chloroaldehydes with the sodium salt of cysteamine 2-alkyl-5.6- ...
