European Journal of Biomedical and Pharmaceutical Sciences

SYNTHESIS AND ANTIBACTERIAL ACTIVITY STUDIES OF ISOXAZOLE SUBSTITUTED COUMARINS

K. Udaya Sree* Dr. A. L. V. Ramana Reddy and T. Bhupal Reddy

ABSTRACT

An efficient and successful attempt is made for the synthesis of 8,9-substituted-3,4-dihydropyrano[2',3':5,6] chromeno[4,3-c]isoxazol-10(3H)-ones(8a-d)and8,9-substitutedpyrano [2',3':5,6] chromeno [4,3-c] isoxazol-10(4H)-ones (12a-d). 7-Hydroxycoumarin-8-carbaldehydes (2) were synthesized from7-hydroxy-4-methyl-coumarin using glacial aceticacid under hot condition. The resulting formyl compound was reacted with allyl bromide in presence of N,N-Dimethylformamide to gave the 7-allyloxy-6,9-substituted-coumarin-8-carbaldehydes (4a–d). These compounds (4a-d) treated with Hydroxylamine hydrochloride yielded 7-allyloxy- 6,9-substituted-coumarin-8-aldehydeoximes (6a-d), which on reaction with ceric ammonium nitrate(9) in acetonitrile gave 8,9-substituted-3,4-dihydropyrano[2',3':5,6]chromeno[4,3-c]isoxazol-10(3H)-ones(8a-d) and similarly 8,9-substitutedpyrano[2',3':5,6]chromeno[4,3-c]isoxazol-10(4H)-ones (12a-d) were synthesized. The structures of all the newly synthesized molecules were assigned by spectral data. The synthesized compounds were screened for their antibacterial activities.

Keywords: 7-Hydroxy-4-methyl-coumarin-8-carbaldehyde, Ceric Ammonium Nitrate, Acetonitrile, Antibacterial activity.