- Thermal rearrangement of allyl substituted unsymmetric 4H-1,2,4-triazoles to the corresponding 1H-1,2,4-triazoles
-
A series of neat 4-(2-alkenyl) substituted 5-methyl-3-phenyl-4H-1,2,4- triazoles were thermolyzed at 320°C producing a rearrangement products, of which the regioisomeric 1- and 2-substituted triazoles were the main products. The group migrations were rationalized in terms of consecutive S N2-type reactions. This mechanism was supported by a study of the alkylations of the triazoles which gave similar product mixtures. 4-(2-alkenyl) substituted 3-phenyl-4H-1,2,4-triazoles, on the other hand, gave predominantly elimination products.
- Jorgensen, Kare B.,Olsen, Ragnhild B.,Carlsen, Per H.J.
-
p. 481 - 495
(2007/10/03)
-
- A Study on Ester Formylhydrazones
-
A series of ester formylhydrazones 2 were synthesized from the reaction of alkyl imidate hydrochlorides 1 with formylhydrazine. Treatment of 2 with hydrazine hydrate, ethyl carbazate and tert-butyl carbazate led to the formation of 3-alkyl-4-amino-, 3-alkyl-4-ethoxycarbonylamino- and 3-alkyl-4-tert-butoxycarbonylamino-4H-1,2,4-triazoles 3-5, respectively. Reaction of compounds 2 with formylhydrazine gave N,N′-diformylhydrazine 6. Compounds 2 were reacted with 2,5-dimethoxytetrahydrofuran to afford 3-alkyl-4-(1H-pyrrol-1-yl)-4H-1,2,4-triazoles 8.
- Ikizler, Aykut A.,Yildirim, Nuri
-
p. 377 - 380
(2007/10/03)
-