Synthesis of Novel Oxazin Analogs of Thio-4-azaspiro[4.5]decan-3-one for their Antimicrobial Activity

The present work reports the synthesis of 4-(1-(substituted phenyl)-1H-naphtho[1,2-e][1,3]oxazin- 2(3H)-yl)-1-thia-4-azaspiro-[4.5]-decan-3-one IV(a-h) by 4-(((substituted phenyl)(2-hydroxynaphthalen- 1-yl) ethyl)amino)-1-thia-4-azaspiro[4.5]decan-3-one with formaldehyde in acetonitrile, containing a spiro ring obtained from the reaction of cyclohexylidene hydrazine and thioglycollic acid in DMF (cyclohexanone reacts with hydrazine hydrate in pyridine). The structures of the synthesized compounds have been established on the basis of elemental analysis, UV-vis absorption spectroscopy, IR, 1H NMR and mass spectral studies. The in vitro antimicrobial screening of all novel compounds was done against S. aureus, E. coli, P. aeruginosa and B. subtilis. The activity of compounds IVb, IVc, IVe and IVf compounds showed moderate to good activity against the tested microbes.