反应详情

For the synthesis of compounds of formula (I) wherein E=--S--, Reaction Schemes 13 and 14 may be utilized. In Reaction Scheme 13, the isothiocyanate 22 is reacted with ethyl carbazate (8) to give the 1-(carbethoxy)thiosemicarbazide 48. By standard conditions, 48 is S-alkylated to yield 49, which can be cyclized to the triazolinone 50 by heating, optionally in the presence of base or acid [F. Kurzer and D. R. Hanks, Chem. Ind. (London), 1143 (1966)]. Finally, alkylation of the triazolinone as in Reaction Scheme 1 provides the fully substituted product 51. ##STR58##

1. customIn Reaction Scheme 13