Reactions and Antibacterial Activity of 6-Bromo-3-(2-Bromoacetyl)-2H-Chromen-2-One

In this investigation, we continued to study the reaction of 6-bromo-3-(2-bromoacetyl)-2H-chromen-2-one (2) with different active compounds in order to synthesize 1,3,4-thiadiazine 4, benzofuran 6, and naphthofuran 8 associated with coumarin moiety. On the other side, 6-bromo-3-(2-hydrazinylthiazol-4-yl)-2H-chromen-2-one (9) allowed to condense with 6-bromo-3-acetylcoumarin (1), phthalic anhydride derivatives 11a,b, or 4-(4-substituted-benzylidene)-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one 14a,b to afford different (2H-chromen-3-yl)thiazol-2-derivatives 10, 12a, 12b, 15a, and 15b, respectively. Six of the newly synthesized compounds were screened for their in-vitro antibacterial activity against Gram-positive bacteria, and Gram-negative bacteria. The results indicated that, compounds 4 and 10 showed strong inhibition activity toward Enterococcus faecalis (Gram-positive bacteria), while 12a revealed strong activity toward Pseudomonas aeruginosa (Gram-negative bacteria).