The pyrazolone derivative 4 was synthesized by reaction of carbohydrazide 2 with ethyl benzoylacetate
in ethanol and p-toluene sulphonic acid followed by cyclization upon heating in acetic acid.
Chloroacylation of amino ester and amino benzoyl compounds 1, 19 gave the chloro acetylamino derivatives
5 and 20 respectively which both of them react with different amines to afford compounds 6, 23a-d.
Hydrolysis and decarboxlation of compound 1 yielded the aminothienotetrahydroisoquinoline 8 which
was used as versatile material for synthesizing other heterocyclic compounds 9-18. Compound 20 react
with hexamethylenetetramine and malononitrile yielded thediazepino and pyrrolo derivatives 21, 22 respectively.