Solvent free synthesis, crystal studies, docking studies and antibacterial properties of some novel fluorinated pyridazinone derivatives

The solvent free synthesis of six 6-(3,5-difluorophenyl)-4,5-dihydropyridazin-3(2H)-one derivatives was carried out by microwave irradiation of a pulverized mixture of 4-(3,5-difluorophenyl)-4-oxobutanoic acid and substituted hydrazine hydrochloride in presence of catalytic amount of acetic acid at 150 °C/75 W for 5 min. Single crystals of two derivatives, C16H12N2OF2 [3a] and C16H11N2OF3 [3f] were formed allowing for structural analysis. [C16H12N2OF2]: orthorhombic, Pbcn; a = 17.1583(5) Å, b = 11.3751(3) Å, c = 13.7704(4) Å, V = 2687.67(13) Å3, Z = 8, 173(2) K, μ(Cu Kα) = 0.920 mm−1, Dcalc = 1.415 g/mm3, 16553 reflections, 2651 unique (Rint = 0.0298); R1 = 0.0394 (I > 2σ(I)) and wR2 = 0.1118 (all data). [C16H11N2OF3]: triclinic, P-1, a = 7.4837(4) Å, b = 13.3707(10) Å, c = 13.7194(9) Å, α = 76.622(6)°, β = 88.771(5)°, γ = 81.453(5)°, V = 1320.60(16) Å3, Z = 4, 173(2) K, μ(Cu Kα) = 1.087 mm−1, Dcalc = 1.530 g/mm3, 8522 reflections, 5092 unique (Rint = 0.0277); R1 = 0.0441 (I > 2σ(I)) and wR2 = 0.1289 (all data). Preliminary antibacterial properties and docking studies are described for all the six derivatives.