Facile synthesis of novel monocyclic trans- and cis-3-oxo/thio/seleno-4-pyrazolyl-β-lactams

Abstract

A facile synthesis of novel monocyclic trans-and cis-3-oxy/thio/seleno-4-pyrazolyl-β-lactams (5, 6) is described. The reaction of 2-methoxy/phenoxy/benzyl/phenylthio/seleno ethanoic acids or acetoxyacetyl chloride 4 with pyrazolyl substituted Schiff′s bases 3a-d using POCl 3 and Et 3 N in refluxing toluene furnished β-lactams (5, 6). These synthesized β-lactams have been characterized by spectroscopic techniques viz. NMR ( 1 H, 13 C and 77 Se), FT-IR, mass spectrometry (EI-MS and HRMS) and elemental analysis. Single crystal X-ray crystallographic study of trans-1-(4′-methoxyphenyl)-3-methoxy-4-(5′-chloro-3′-methyl-1′-phenyl-1H-pyrazol-4′-yl)azetidin-2-one 5p has confirmed the molecular structure and the stereochemical outcome. The cis or trans configuration of β-lactams (5, 6) was assigned with respect to position of C3-H and C4-H.

Synthesis, Antimicrobial, Antioxidant, Toxicity and Anticancer Activity of a New Azetidinone, Thiazolidinone and Selenazolidinone Derivatives Based on Sulfonamide

“…2-Azetidinones have been found to act as cholesterol acyl transferase inhibitors, thrombin inhibitors, human cytomegalovirus protease inhibitors, matrix metalloprotease inhibitors, cysteine protease, and apoptosis inductors [6]. The biological activity is usually associated with the nature of the groups linked to N-1, C-3, and C-4 of the 2-azetidinone molecules [11]. 2-Azetidinone derivatives containing β-lactam nucleus have a wide range of pharmaceutical activity and have become an integral part of the chemotherapeutic arsenal available to today's medical practitioners [12].…”

“…The proton of azomethine group (CH=N) of compounds (2a-2e, 2g) appears at δ 8.58-9.07 ppm [21]. The 2azetidinone compounds (Z 2 a-Z 2 e and Z 2 g) are characterized by showing doublet signal at δ 3.02-4.17 ppm and at δ 4.22-6.05 ppm, which can be assigned to the (CH-N) and (CH-Cl) protons, respectively and disappearing the azomethine signal that exists in Schiff bases (2a-2e and 2g) [11,36]. The 1 H-NMR spectra of the 4-thiazolidinones and 4-selenazolidinones (Z 2 B, Z 2 E, Z 2 B' and Z 2 E') are characterized by showing singlet signals at δ 3.03-3.67 ppm and at δ 3.25-3.74 ppm, which attributed to the (CH 2 -S) and (CH 2 -Se) protons respectively [21,37].…”

“…The 13 C-NMR spectra of azetidine-2-ones, 1,3thiazolidin-4-ones and 1,3-selenazolidin-4-ones show signals at the range δ 168. 48 47 ppm and which can be assigned to the C-Cl and C-N in lactam ring, respectively [11]. Also, the spectra of the thiazolidine-4-one or selenazolidin-4-one derivatives exhibited two signals at δ 56.17-58.47 and δ 31.22-35.66 ppm, which can be assigned to the 2-C and 5-C in 1,3thiazo or 1,3-selenazolidin-4-one ring, respectively [21,39].…”

Synthesis, characterization and biological Activity of β-Lactam and Thiazolidinone Derivatives Based on Sulfonamide

“…The crude product was purified by silica gel column chromatography using 3:7 ethyl acetate / hexane as eluent to afford pure products. [11] The Rf values of all the compounds were determined by using Ethyl acetate: n-Hexane (2:8) as solvent system. The synthetic procedures for the preparation of compounds (Z5A1-Z5A6, Z5A9-Z5A12, Z5A2' , Z5A9' -Z5A11' )are presented in Scheme 1.…”

“…[6] The biological activity is usually associated with the nature of the groups linked to N-1, C-3 and C-4 of the β-lactam molecules. [11] 2-Azetidinone derivatives containing βlactam nucleus have a wide range of pharmaceutical activity and become an integral part of the chemotherapeutic arsenal available to today's medical practitioners. [12] Thiazolidin-4-ones are thiazolidine derivatives and have an atom of sulfur at position 1, an atom of nitrogen at position 3 and a carbonyl group at position 4.…”