One-pot and solvent-free synthesis of 3-(9-hydroxy-3-methoxy-7-aryl-6,7,9,10- tetrahydro-5H -benzo[h]thiazolo[2,3-b]quinazolin-9-yl)-2H -chromen-2-ones and their antibacterial evaluation

Authors : RAVIBABU VELPULA, JANARDHAN BANOTHU, RAJITHA GALI, YAKAIAH SARGAM, RAJITHA BAVANTULA

Pages : 620-629

Doi:10.3906/kim-1410-64

View : 13 | Download : 12

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A series of 3-insert ignore into journalissuearticles values(9-hydroxy-3-methoxy-7-aryl-6,7,9,10-tetrahydro-5$H$-benzo[$h$]thiazolo[2,3-$b$]quinazolin-9-yl);-2$H$-chromen-2-ones insert ignore into journalissuearticles values(5a-j); were synthesized by one-pot multicomponent reaction of 6-methoxy-1-tetralone, aryl aldehydes, and thiourea followed by cyclization with 3-insert ignore into journalissuearticles values(2-bromoacetyl);-2$H$-chromen-2-one in the presence of a Bronsted solid acid catalyst, polyinsert ignore into journalissuearticles values(4-vinylpyridinium);hydrogen sulfate [Pinsert ignore into journalissuearticles values(4-VPH);HSO$_{4}$] insert ignore into journalissuearticles values(0.015 g);, under solvent-free conditions at 120 $^{\circ}$C. All the synthesized compounds were characterized by spectral studies and screened for their in vitro antibacterial activity against S. aureus and B. thuringiensis insert ignore into journalissuearticles values(gram positive);, and E. coli and K. pneumoniae insert ignore into journalissuearticles values(gram negative); bacterial strains. On comparing with the standard drug gentamicin, compounds derived from 4-methoxy and 3,4,5-trimethoxy benzaldehyde, i.e. 5g and 5h, showed broad spectrum antibacterial activity and the remaining compounds showed weak to moderate activity.
Keywords : Quinazolinethiones, thiazoloquinazolines, poly 4 vinylpyridinium, hydrogen sulfate, one pot and solvent free method, antibacterial activity