Synthesis, characterization and antimicrobial study via new heterocyclic derivatives of trimethoprim

<p>New compounds of trimethoprim heterocyclic derivatives were synthesized. These compounds were synthesized through the condensation reaction between trimethoprim with bromoacetic acid to yield compound <b>1</b>. Several Schiff bases <b>2</b>–<b>7</b> have been synthesized by the condensation different aromatic aldehydes with compound <b>1</b>. Compound <b>8</b> were formed from the reaction of sodium nitrite and acetyl acetone in presence of conc. hydrogen chloride to obtain the hydrazono derivative; then, Cyclocondensation of compound <b>8</b> with hydrazine hydrate, phenyl hydrazine and dinitrophenyl hydrazine respectively to yield compounds <b>9</b>–<b>11</b> in ethanol affording the pyrazoline derivatives. This work involves the synthesis of some 1,2,3-Triazoles derived from compound <b>1</b> by the action of sodium azide on the diazonium chloride salt to yield 5-azido-8-(3,4,5-trimethoxybenzyl)imidazo[1,2-c]pyrimidin-3(2H)-one <b>12</b>. Finally, by reaction of 12 with acetyl acetone and ethyacetoacetate; respectively in sodium ethoxide/ethanol as a solvent to form compounds <b>13</b>, <b>14</b>. The structures of the compounds <b>1</b>–<b>14</b> were characterized by elemental analysis, spectral data and antimicrobial evaluation of the some newly synthesized compounds and found that the synthesized compounds are active against tested Gram positive and Gram negative bacteria like <i>Staphylococcus aureus, Bacillus subtilis, Escherichia coli</i> and <i>Proteus.</i> </p