Synthesis of Triazolo and Pyrazolo Derivatives of Quinoline Nucleus

摘要

New heterocyclic derivatives of quinoline are reported. Reaction of quinoline-2-thiol 4 with hydrazine hydrate gave 2-hydrazionoquinoline 5 . Treatment of 5 with CS 2 in pyridine afforded 1,2,4-triazolo-[4,3-a]-quinolin-1-2H-thione 6 , whereas the reaction of 5 with carboxylic acids namely formic acid or acetic acid, yielded the 1,2,4-triazol-[4,3-a]-quinolin 7 or 5-methyl-1,2,4-triazolo [4,3-a]-quinoline 8 through ring closure. Diazotization of 5 under acidic conditions produced the fused tetrazole compound 9 , tetrzolo-[1,5-a]-quinoline. Moreover, treatment of 5 with active methlyene compounds gave two pyrazole derivatives 10 and 11 . Azomethines 12a-e were prepared through condensation of 5 with aromatic aldehydes or ketones. Keyword : triazoloquinoline, tetrazoloquinoline, pyrazoloquinolines, azomethines.