141859-18-9Relevant academic research and scientific papers
CONDENSATION OF 5-AMINOISOTHIAZOLES WITH N-METHYLIMIDOYL CHLORIDE. RING-TRANSFORMATION WITH PARTICIPATION OF 10-S-3 TYPE SULFURANE
Ohkata, Katsuo,Watanabe, Yuko,Ohyama, Yoshihiko,Akiba, Kin-ya
, p. 763 - 774 (2007/10/02)
In the presence of 1,4-diazabicyclooctane, 5-amino-3-methylisothiazole (4a) in acetonitrile condensed with N-methyl-p-chlorobenzimidoyl chloride (5a) to afford two kinds of compounds along with several minor products.One of the two was 1:1 condensed product (6a) and the other was 2:1 condensed product (7a).The latter compound was obtaind in higher yield when an excess 4a was treated with 5a.On the other hand, in the absence of the additional base, 2:3 condedsed compound (8a) was isolated as a major product besides 6a and 7a. 8a was obtained by treatment of 7a with 2 equiv. of imidoyl chloride in 21 percent yield.Reaction of 5-amino-3-phenylisothiazole (4b) with imidoyl chloride (5a,b) furnished the analogous products.On the other hand, condensation of 5-amino-3-phenylisoxazole (4c) with 5a furnished the oxygen analogue (6d) corresponding to 6b as a sole isolated product.The formation of 7 is explained by ring-transformation from isothiazole into thiadiazole via hypervalent 10-S-3 type sulfurane (B).
