Synthesis, Characterization, and Antimicrobial Activity of Some New Thiophene Derivatives and Crystal Structure of Ethyl [4-(2-Thienylmethylene)Aminophenoxy]Acetate

This work describes facile routes towards the synthesis of some novel thiophene derivatives. Thus, condensation of thiophene-2-carboxaldehyde with 4-aminophenol furnished the Schiff base, 2-[(4-hydroxyphenyl)iminomethyl]thiophene. Reaction of the Schiff base with ethyl chloroacetate or chloroacetamide gave ethyl (4-(2-thienylmethylene)aminophenoxy]acetate and [4-(2-thienylmethylene)aminophenoxy]acetamide respectively. Alkylation of the Schiff base with some 1-bromoalkanes afforded alkyloxyphenylaminomethylenethiophene derivatives. The title compounds were characterized by elemental analysis, infrared (IR) and 1 H NMR spectroscopy. In addition, the molecular structure of ethyl [4-(thiophene-2-ylmethylene)aminophenoxy]acetate was further confirmed by single-crystal X-ray diffraction which its crystals are found to be monoclinic and the space group is P 2 1 / c with the lattice parameters a = 8.961(2) Å, b = 12.236(3) Å, c = 12.996(3) Å, β = 93.629 (3)° and V = 1422.1(5) Å 3 . Moreover, all synthesized compounds were screened in vitro for their antimicrobial activity and promising results obtained.