Abstract: Four new dehydroabietylamine Schiff bases, i.e.,(E)-1-DHAA-N-((5-nitrofuran-2-yl)methylene)(1),(E)-N-(furan-2-ylmethylene)-1-DHAA(2),(E)-N-((5-bromofuran-2-yl)methylene)-1-DHAA(3), (E)-1-DHAA-N-((5-methylfuran-2-yl)methylene)(4), were prepared from furfural derivative and dehydroabietylamine(DHAA). The process conditions were optimized by single factor and orthogonal experiment. The yields of Schiff bases 1-4 were 89.5%, 89.1%, 90.2% and 88.1%, respectively. Their structures were characterized and confirmed by X-ray single crystal diffraction, NMR, MS, IR. Both Schiff base 1 and 2 belonged to orthorhombic system, space group P2(1)2(1)2(1), Schiff base 3 belonged to monoclinic system, space group P2(1). The practical structural parameters were in agreement with the calculated chemical simulation results. The bond lengths of the DFT algorithm were 0.127 67, 0.127 91 and 0.127 88 nm, respectively, while the results of the single crystal diffraction analysis were 0.127 5(5), 0.126 1(5) and 0.124 5(7) nm. The simulated values of bond angle of C(20)-N(1)-C(21) were 121.610 1, 120.760 7 and 120.813 5°, respectively, and the actual values of the single crystal test were 119.1(3), 117.3(3), and 117.4(5)°. The antibacterial activities of 4 Schiff bases were studied, which showed that the minimum inhibitory concentration of Schiff base 1 on Staphylococcus aureus was 0.31 g/L, which was equivalent to the positive control of cephanisisi, indicating a higher antibacterial activity; the minimum bacteriostatic concentrations of Schiff base 1, 3 and 4 against Escherichia coli were 0.62 g/L, and the antimicrobial activity was significantly better than Schiff base 2.

Key words: dehydroabietylamine, carbonyl aldehyde condensation, X-ray single crystal diffraction, computational chemistry, antibacterial properties