ONE—POT SYNTHESIS OF PYRIDINES, THIENOPYRIDINES, PYRROLOTHIENOPYRIDINES AND (1,8) NAPHTHYRIDINES UNDER PHASE-TRANSFER CATALYSIS CONDITIONS

Abstract

A new series of pyridines 2_a,b , (1,8) naphthyridines 3_a,b and diazepines 4_a,b were synthesized in one-pot reaction under phase-transfer catalysis conditions (PTC) starting with cyanoketene S,S-acetals 1 and cyanothioacetamide, cyanoacetamide or cyanoacetohydrazide in different molar ratios. The reaction of 2_a with halo compounds in equimolar ratio gave thienopyridines 5_a-d , while on using 1:2 molar ratio afforded pyrrolothienopyridines 6_a-d. Also, bis thieno (1,8) naphthyridines 7_a-d , bis-pyrrolo (1,8) naphthyridine 9 and bis (1,6) naphthyridines 10_a-c were obtained by treating (1,8) naphthyridine 3_a with the suitable reagents.

Key Words:

• Naphthyridines
• thienopyridines
• pyrrolothienopyridines bis-thienonaphthyridines
• PTC