Ahmed T. Abdel-Aziz

Synthesis of 1,3-thiazolidin-4-ones; reactivity of the thiosemicarbazone function towards dimethyl acetylenedicarboxylate

Aryl thiosemicarbazones react rapidly in a facile procedure with dimethyl acetylene-dicarboxylate to give substituted (ylidene) hydrazono(4-oxothiazolidin-5-ylidene) acetates in high yields. The synthesised compounds were characterised by spectroscopic methods and the structures confirmed by single crystal X-ray crystallography. Several mechanistic options involving nucleophilic interaction are presented.

Synthesis and antibacterial activity of new substituted ethylidenehydrazinylidene-1,3-thiazol-4-ones

A series of substituted ethylidenehydrazinylidene-1,3-thiazol-4-ones and dimethyl 2-{[4-1(-[5-(2-methoxy-2-oxoethylidene)-4-oxo-3-phenyl-1,3-(thiazolidin-2-ylidene]hydrazonylidene}ethyl)phenyl]aminofumarate were synthesised by condensation of substituted ethylidene-N-phenylhydrazinecarbothioamides with dimethyl acetylenedicarboxylate. The synthesised compounds were characterised by spectroscopic methods and confirmed by single crystal X-ray crystallography. Some of the prepared compounds were screened for their in vitro antibacterial activity against different strains of microorganisms, compound 3b exhibited significant antibacterial activity against Pseudomonas aeruginosa compared to ciprofloxacin with MIC value of 1.12 μg mL−1.

Facile and convenient synthesis of 2,4-disubstituted and 2,3,4-trisubstituted 1,3-thiazoles

ABSTRACT An efficient route for the synthesis of (E)-2-(2-(2-nitrobenzylidene)-hydrazinyl)-4-phenylthiazol-3-ium bromide, (E)-2-(2(substituted benzylidene)hydrazinyl)-4-phenylthiazoles and (E)-4-(4-bromophenyl)-2-(cycloalkylidenehydrazono)-3-phenyl-2,3-dihydrothiazoles by reaction of 1-aryl-2-bromoethanones with 2-(1-substituted methylidene)hydrazinecarbothioamides and cycloalkylidene-N-phenyl-hydrazinecarbothioamides. The structure of the products has been confirmed by using IR, NMR, mass spectrometry and single-crystal X-ray analyses. GRAPHICAL ABSTRACT

Crystal structure of 3-benzyl-1-[(1,2,3,4-tetra­hydro­naphthalen-1-yl­idene)amino]­thio­urea

In the title compound, C18H19N3S, the dihedral angle between the planes of the benzene rings is 58.63 (8)°. The six-membered ring bonded to the thiosemicarbazide group (r.m.s. deviation = 0.038 Å) adopts a sofa conformation, with one of the methylene-group C atoms as the flap. A short intramolecular N—H⋯N contact is observed. In the crystal, molecules are linked by weak N—H⋯S interactions to generate C(4) chains propagating in the [010] direction, with adjacent molecules related by glide symmetry.

Crystal structure of 3-benzyl-1-[(cyclo-hexyl-idene)amino]-thio-urea.

The conformation of the title compound, C14H19N3S, is partially determined by an intramolecular N—H⋯N hydrogen-bond interaction, although the N—H⋯N angle of 108° is quite small. The cyclohexylidene ring has a chair conformation and its mean plane is inclined to the benzene ring by 46.30 (8)°. In the crystal, molecules are linked by pairs of N—H⋯S hydrogen bonds, forming inversion dimers, with an R 2 2(8) ring motif. The dimers are reinforced by pairs of C—H⋯S hydrogen bonds, and are linked by further weak C—H⋯S hydrogen bonds, forming chains propagating along [100].

Crystal structure of 1-(cyclo-pentyl-idene-amino)-3-(prop-2-en-1-yl)thio-urea.

In the title compound, C9H15N3S, the cyclopentyl ring adopts an envelope conformation with one of the methylene C atoms as the flap. The thiosemicarbazide fragment is almost planar (r.m.s. deviation = 0.038 Å) and a short intramolecular N—H⋯N contact occurs. In the crystal, molecules are linked into helical (41 symmetry) chains propagating in [001] by N—H⋯N and N—H⋯S hydrogen bonds. A very weak C—H⋯S interaction is also observed.

Crystal structure of 3-(prop-2-en-1-yl)-1-{[(1E)-1,2,3,4-tetra-hydro-naphthalen-1-yl-idene]amino}-thio-urea.

In the title compound, C14H17N3S, the dihedral angle between the planes of the benzene ring and the thiosemicarbazone group (r.m.s. deviation = 0.031 Å) is 8.45 (4)°. A short intramolcular N—H⋯N contact is seen. In the crystal, weak N—H⋯S hydrogen bonds connect the molecules into C(4) chains propagating in the [010] direction, with adjacent molecules in the chain related by 21 screw-axis symmetry.