A Convenient Synthesis of 3-Alkyl-6-trifluoromethyl-3,6-dihydro-2<i>H</i>-1,3,4-thiadiazines
作者:Yasuhiro Kamitori、Masaru Hojo、Ryōichi Masuda、Yoshihiko Kawamura、Tōru Numai
DOI:10.1055/s-1990-26915
日期:——
3-Dialkylhydrazono-1,1,1-trifluoro-2-alkanones 2, readily obtainable from the reaction of substituted benzaldehyde, propanal and formaldehyde dialkylhydrazones with trifluoroacetic anhydride, afford title compounds 5 in satisfactory yields on treatment with Lawesson reagent in refluxing benzene.
Diastereoselective synthesis of 3,6-dihydro-2H-1,3,4-thiadiazines
作者:Jean-Damien Charrier、Alain Reliquet、Jean Claude Meslin
DOI:10.1016/s0957-4166(98)00108-6
日期:1998.5
Thionation of the benzil hydrazones 3 with Lawesson's reagent afforded the 3,6-dihydro-2H-1,3,4-thiadiazines 4 by an intramolecular cyclisation. This reaction was shown to be diastereospecific and allowed the formation of the exo compounds 4b-e. When the homochiral SAMP-hydrazone 3f was used, the reaction afforded enantiomerically pure (4R,6R,9S)-4f. (C) 1998 Elsevier Science Ltd. All rights reserved.