A convenient synthesis and hepatoprotective activity of imidazo[1,2-c]pyrimido[5,4-e]pyrimidine, tetraazaacenaphthene and tetraazaphenalene from cyclic ketene aminals through tandem addition-cyclization reactions.
A novel one-pot synthesis of imidazo[1,2-c]pyrimido[5,4-e]pyrimidinones (2), tetraazaacenaphthene-3,6-diones (4), tetarazaphenalene-1,7-dione (4d) is delineated from the reaction of cyclic ketene aminal (1) and alkyl or aryl isothiocyanate through tandem addition-cyclization reactions. However, reaction of ketene aminal (1a) with alkyl isothiocyanate only yielded angularly cyclized product 5 which did not react further to yield 6. The structure of 2c and 4d was ascertained by single crystal X-ray diffraction analysis which demonstrated a network of various inter- and intramolecular interactions, responsible for the stability and packing of the molecules in the crystalline state. Some of the compounds (2a--h) were screened for hepatoprotective activity but only 2a was found most effective.
Ram
Vishnu J
VJ
Division of Medicinal Chemistry, Central Drug Research Institute, 226 001, Lucknow, India. vjiram@yahoo.com
Goel
Atul
A
Sarkhel
Sanjay
S
Maulik
Prakas R
PR
D000073:Acenaphthenes / Q000138:chemical synthesis; D000818:Animals; D000975:Antioxidants / Q000138:chemical synthesis; D001372:Aza Compounds / Q000138:chemical synthesis; D018360:Crystallography, X-Ray; D003500:Cyclization; D006801:Humans; D007659:Ketones / Q000138:chemical synthesis*; D008107:Liver Diseases / Q000188:drug therapy / Q000517:prevention & control; D015394:Molecular Structure; D020011:Protective Agents / Q000138:chemical synthesis*; D011744:Pyrimidinones / Q000138:chemical synthesis
D000073:Acenaphthenes; D000975:Antioxidants; D001372:Aza Compounds; D007659:Ketones; D020011:Protective Agents; D011744:Pyrimidinones