Synthesis of 2-(2-R1-Hydrazino)-5-(R2-benzyl)-2-thiazolines on the Basis of Meerweins Arylation Products of Allyl Isothiocyanate

3-Aryl-2-chloropropylisothiocyanates (1) are formed by interaction of arenediazonium chlorides with allyl isothiocyanate. Adducts 1 react with monoacylhydrazines to form 1-acyl-4-(3-aryl-2-chloropropyl)thiosemicarbazides (2a–d). Thiosemicarbazides 2a–d in the presence of bases selectively transform into 2-(2-R1-hydrazino)-5-(R2-benzyl)-2-thiazolines (3a–d)