Thiosemicarbazide Derivatives as Building Block in Synthesis of Target Heterocyclic Compounds with Their Antimicrobial Assessment

Abstract

1‐(2‐Benzamido‐3‐(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)acryloyl)‐4‐phenylthiosemicarbazide is used as precursor for synthesis of imidazole, 1,3,4‐oxadiazole, 1,3,4‐thiadiazole, 1,3‐oxazine, and 1,2,4‐triazine ring systems. The antimicrobial activity of some of the synthesized compounds was tested.

New Benzimidazole-, 1,2,4-Triazole-, and 1,3,5-Triazine-Based Derivatives as Potential EGFRWT and EGFRT790M Inhibitors: Microwave-Assisted Synthesis, Anticancer Evaluation, and Molecular Docking Study

“…On the other hand, treatment of compounds 2a , b , d , and e with hydrazine hydrate or phenyl hydrazine under microwave irradiation afforded the corresponding 1,3,4-triazole derivatives 5a – c and 6a – c , respectively, as the reported methods. 91 − 94 IR spectral data of the latter triazole derivatives were devoid of any absorption bands correlated to C=O or C=S groups; instead, they exhibited absorption bands at 3288–3199 cm –1 contributing to NH groups, 3328 cm –1 referring to OH of compound 5c , and 1664–1639 cm –1 due to C=N groups. Furthermore, 1 H NMR data of compounds 5 and 6 showed singlet signals at the region δ 4.23–3.50 ppm representing the presence of the two methylene protons of CH 2 -ph and D 2 O exchangeable signals at the range δ 7.21–12.31 ppm due to NH and OH protons, in addition to the expected multiplet signals at δ 6.60–8.38 ppm representing the aromatic protons.…”

“…The chemical structures of the new compounds were elucidated using microanalytical and spectral data (IR, 1 H, 13 C NMR, MS). 2-Phenylacetyl isothiocyanate (1) was utilized as a key starting material and treated with different aliphatic, heterocyclic, and/or aromatic amines, namely, isopropylamine, 2-aminothiazole, o -phenylenediamine, m -aminophenol, and o -chloro- p -nitroaniline, in acetonitrile at room temperature 91 to afford the corresponding thiourea derivatives 2a – e , respectively. IR spectra of 2a – e represented characteristic absorption bands at the regions 3370–3135, 1690–1660, and 1173–1146 cm –1 due to NH, C=O, and C=S groups, respectively.…”

“…On the other hand, microwave irradiation of compounds 2a , b , d , and e with thiourea led to the formation of the corresponding 1,3,5-triazin-2-thione analogues 8a – d , respectively ( Scheme 2 ), following the reported reactions. 91 − 94 The IR spectrum of compound 7 showed a characteristic absorption band at 1685 cm –1 characteristic for the carbonyl group of the triazine ring, in addition to an absorption band at 3206 cm –1 due to NH moieties. IR spectra of compound 8 exhibited the C=S group as an absorption band at the region1177–1127 cm –1 .…”

“…The chemical structures of the new compounds were elucidated using microanalytical and spectral data (IR, 1 H, 13 C NMR, MS). 2-Phenylacetyl isothiocyanate (1) was utilized as a key starting material and treated with different aliphatic, heterocyclic, and/or aromatic amines, namely, isopropylamine, 2-aminothiazole, o-phenylenediamine, m-aminophenol, and ochloro-p-nitroaniline, in acetonitrile at room temperature 91 Microwave irradiation of the thiourea derivative 2c in DMF for 2 min led to its cyclization, forming the corresponding N-(1H-benzo[d]imidazol-2-yl)-2-phenylacetamide benzimidazole (3), while its microwave irradiation with benzoyl chloride afforded 92,93 the corresponding N-(2-phenyl-1H-benzo[d]imidazole-1-carbonothioyl) benzamide (4) (Scheme 1). IR spectra of the later derivatives 3 and 4 exhibited absorption bands at the ranges 3220−3128 and 1670−1699 cm −1 correlated to NH and CO groups, respectively.…”

Pyrazole-carboxaldehydes as versatile precursors for different pyrazole-substituted heterocyclic systems

“…Gaffer et al 150 reported that condensation of pyrazolin-5-one derivative 111 with Pyrazolecarboxaldehyde 2 in acetic acid and fused sodium acetate yielded the corresponding condensation product 112 which underwent further heterocyclization reaction with bromoacetone and phenacyl bromide 101 to give the corresponding thiazolyl-pyrazole derivatives 113 (Scheme 48). Abou Elmagd et al 123 reported that heating of thiosemicarbazide 67 124 The reaction of α,β-unsaturated ketones 42 with malononitrile 53 in ethanol at reflux in the presence of ammonium acetate afforded the corresponding 2-amino-3-cyano-pyridine derivatives 156. 112,114,154 On the other hand, a reaction of 42 with 53 in the presence of either sodium methoxide/ methanol or sodium ethoxide/ ethanol gave the corresponding 2-alkoxynicotinonitriles 157 155 (Scheme 66).…”