Four biologically active Schiff bases of benzylidene derivatives (6-9), namely, 4-Hydroxy-3-methoxy-benzylidene-phenylamine (6), 4-Hydroxy-3-methoxy-benzylidene-2-methyl-phenylamine(7), 4-Hydroxy-3-methoxy-benzylidene-4-methyl-phenylamine (8) and 4-Hydroxy-3-methoxy-benzylidene-imino-phenylamine (9), were prepared. Also, with the aim of developing new compounds contain both of phenoxy and amide groups together in their skeletons in intent to possess a broad biological effects, six novel dimethylcarbamoylmethylene derivatives (15-20), namely, [N-(2-methylphenyl)]-carbamoylmethylene-2-methyl-phenoxide(15), [N-(2-methylphenyl)]-carbamoyl-methylene-3-methyl-phenoxide (16), [N-(2-methylphenyl)]-carbamoyl- methylene-4-methyl-phenoxide (17), [N-(4-methylphenyl)]-carbamoylmethylene-2-methyl-phenoxide (18), [N-(4-methyl-phenyl)]-carbamoylmethylene-3-methyl-phenoxide (19) and [N-(4-methylphenyl)]-carbamoylmethylene-4-methyl-phenoxide (20), were synthesized. All compounds were purified by crystallization and recrystallization resulted in pure crystals. The physical constants, melting points, Rf values in different solvents systems were recorded. Both of IR spectrum and MS spectrum of these compounds were in full agreement with their assigned chemical structures.
The bacteriological efficiency of the new synthesized compounds was evaluated on three microorganisms, one of useful bacteria (Sarcina urea), one pathogenic bacteria (Staphylococcus aureus) and one useful yeast (Saccharomyces cerevisiea).
The Propagation of the S. cerevisiea was accelerated by both of (9) and (6), which mean that the absence of the substitution at ortho- or para- positions with methyl group has good effect on the yeast. On the other hand, the survival of the S. cerevisiea was inhibited by both of (7) and (8). Also, the Proliferation of the S. aureus was inhibited by (9), (6) and (7). This means that these compounds could be used as germicidals. Both of (6) and (9), which have no methyl group at ortho- or para-positions were activated the proliferation of the S. urea. Both of (8) and (7) were also activated the S. urea but in ratio less than the two latter compounds.
The survival of the S. urea was activated by all of the dimethylcarbamoyl- methylene derivatives (15-20), specially the compounds (16), (17) and (18). Also, the propagation of the yeast, S. cerevisiea, was also activated by all the derivatives (15-20) and the maximum activation were observed by each of (15), (16) and (18). These derivatives (15-20) were represented a highly germicidal effect towards the pathogenic bacteria S. aureus. Both of (15) and (19) reflect the maximum germicidal activity. It could be concluded that the substitution by the methyl group in the phenyl ring (anilide) at para- or ortho-positions with the substitution in the phenoxide ring at ortho- or meta- positions by methyl group, which represented by (18), (16) and (15), were reflected the highly biological activation. This means that these compounds could be use to accelerate the stimulation of the nitrogen fixers bacteria group in their growth media and also accelerate the fermentation process in the industrial processes.