REACTION OF 3-AMINO-2H-AZIRINES WITH DIPHENYLCYCLOPROPENETHIONE

Reaction of 3‐Amino‐2H‐azirines with Diphenylcyclopropenethione 3‐Dimethylamino‐2H‐azirines (4a, 4b) react with diphenylcyclopropenethione (8) to give 4(3 H)‐pyridinethione derivatives of type 10 Scheme 3. The reaction mechanism for the formation of 10 is given in Scheme 3 by analogy with a previous reported one [4] [5]. Hydrolysis of the 4(3 H)‐pyridinethione 10a yields 2‐oxo‐2, 3‐dihydro‐4(1 H)‐pyridinethione (11) and reduction of 10a with sodium borohydride leads to the 2, 3‐dihydro‐4 (1 H)‐pyridinethione 12 Scheme 4. The results of the reaction of 4a, 4b and the thione 8 demonstrate the similarity to the reaction of 4a, 4b and 2 [5] cf. Scheme 1. In contrast, the reactions of imines of type 7a with 2 and 8, respectively, lead to different products (cf. [1] [6]). Copyright © 1979 Verlag GmbH & Co. KGaA, Weinheim