SYNTHESIS OF HETEROCYCLIC NITROGEN COMPOUNDS BY CLOSURE REACTIONS USING TETRAACETYLETHANE WITH VARIOUS PRIMARY AMINES

This work includes synthesis of new five, six, and seven-heterocyclic nitrogen compounds by closure reactions of tetraacetylethane (3) with primary amines in refluxing ethanol and acetonitrile as solvents and without using any catalysts. The tetraacetylethane melting point 184-189 ºC was prepared by condensation of two anhydrous molecules of sodium salt of acetylacetone and in the presence of dry ether as solvents and Iodine as a catalysts. The heterocyclic nitrogen compounds as: 1,4,5,8-tetramethyl-4a,8a-dihydropyridazino[4,5-d]pyridazine (11), 3,7-bis (2,4-dinitrophenyl)1,4,5,8-tetramethyl-4a,8a- dihydropyridazino [4,5-d]pyridazine (12), 1,4,5,8-tetramethyl-1,4a,5,8a-tetrahydro-oxazino[4,5-d]oxazine (13), 4,4′,6,6′-tetramethyl-[5,5′-bipyrimidine]-2,2′(5H,5H’)-dione (14), 2,2′,4,4′-tetramethyl-3H,3H’-3,3′-bibenzo[b][1,5]diazepine (15), (4,6-dimethyl-1, 3 dimethyl enepyrrolo[3,4-c]pyrrole-2,5-diyl)bis(ethan-1-amine) (16), 4,4′-(4,6-dimethyl-1,3-dimethylene pyrrolo[3,4-c]pyrrole 2,5-diyl) dibenzoic acid (17), 2,5-bis(4-bromophenyl)-4,6-dimethyl-1,3-dimethylene-pyrrolo[3,4-c] pyrrole (18), 1,1′-((4,6-dimethyl-1,3-dimethylenepyrrolo[3,4-c] pyrrole -2,5-diyl) bis (4, 1-phenylene)) bis (ethan-1-one) (19), were prepared via condensation of compound (3) with primary amines (e.g. , hydrazine hydrate and primary aromatic amines) in 1:2 molar ratios. The compounds (11-19) were also synthesized by microwave irradiation of starting materials without using any solvent to give excellent yields of these compounds ranging between 80-95. Compounds (11-19) have been identified by spectroscopic methods, IR, UV, 1H-NMR, 13C-NMR (DEPT. 90 and DEPT. 135) and elemental analysis (C.H.N).