Unusual reaction of chloroacetyl chloride with 1,2-dichloroethene. Synthesis and properties of 2-chlorovinyl dichloromethyl ketone

The reaction of chloroacetyl chloride with 1,2-dichloroethene in the presence of AlCl₃ unexpectedly led to the formation of (E)-1,1,4-trichlorobut-3-en-2-one whose structure was proved by ¹H and ¹³C NMR, IR, and mass spectra and independent synthesis. A probable reaction scheme was proposed, which involves transformation of initially formed 1,2,4-trichloro-3-oxobutan-2-yl cation by the action of AlCl₃. The high reactivity of the vinylic halogen atom in (E)-1,1,4-trichlorobut-3-en-2-one was demonstrated by its reactions with nitrogen-centered nucleophiles (triethylamine, aniline, 3,5-dimethyl-1H-pyrazole) and sodium sulfide. These reactions involved only the C-Cl bond in the vinyl fragment and afforded (4,4-dichloro-3-oxobut-2-en-1-yl)triethylammonium chloride, 1,1-dichloro-4-phenylaminobut-3-en-2-one, 1-(4,4-dichloro-3-oxobut-2-en-1-yl)-3,5-dimethyl-1H-pyrazole, and 4,4′-thiobis(1,1-dichlorobut-3-en-2-one), respectively. The reaction of 1,1,4-trichlorobut-3-en-2-one with benzylhydrazine gave a mixture of 1,3- and 1,5-disubstituted pyrazoles.     

An efficient and easily retrievable dip catalyst based on silver nanoparticles/chitosan-coated cellulose filter paper

Re-use of a catalyst is an important task, which is usually achieved by loading it on easily separable supports such as magnetic substrates. However, we demonstrate here the process of easy and fast catalyst separation from a reaction medium by loading it onto an economically feasible and microscopically high surface substrate of filter paper (FP) made up of cellulose microfibers as catalyst support. To achieve the goal, we coated chitosan (CH) on filter paper (CH-FP) to impart a high affinity of the substrate for metal ion absorption. AgNO₃ dissolved in water with a 0.1 M concentration was used as the Ag ion carrier solution, and CH-FP strips with known rectangular dimensions were submerged into it for the metal ion absorption. The metal ion-laden CH-FP strips were dip treated with sodium borohydride (NaBH₄) aqueous solution to prepare Ag-nanoparticle loaded CH-FP (Ag/CH-FP). X-ray diffraction and energy dispersive X-ray spectroscopy confirmed the formation of the Ag/CH-FP hybrid. Ag/CH-FP morphology was examined through scanning electron microscopy analysis, which showed the presence of Ag nanoparticles attached to the cellulose microfibers. The prepared Ag/CH-FP was employed as a dip catalyst for the degradation of nitroarene compounds of 2-nitophenol (2-NP) and 4-nitrophenol (4-NP) by NaBH₄. Remarkably, the rate constants for 4-NP and 2-NP were 3.9 × 10^?3 and 1.7 × 10^?3 s^?1, respectively. In addition, we discussed the ease of the catalyst retrievability from the reaction mixture and its re-usability.     

The synthesis of facial amphiphile 3α,7α-diaminocholestane

The facial amphiphile 3α,7α-diaminocholestane 3 was synthesized from 3β-acetoxy-7-ketocholestane 1 through a stepwise reductive amination. The reductive amination of 1 with NH₄OAc in the presence of NaBH₃CN, and protection with Boc₂O yielded 7α-(tert-butyloxycarbonyl)-aminocholestane 4 in 86% yield. The reductive amination of 6, which was obtained from 4 after hydrolysis and subsequent oxidation, with NH₄OT_f in the presence of NaBH(OEh)₃ provided 3 in 75% yield after protection with Boc₂O.     

Corrosion inhibition of mild steel in hydrochloric acid using extract of glycine max leaves

Research on Chemical Intermediates - The activity of glycine max leaves extract against corrosion of mild steel in 0.5 M HCl solution has been investigated at different temperatures...     

Ruthenium(II) complexes with mono and ditertiary arsines and phosphines and their reaction with small molecules

Dichlorotetrakis(dimethylsulphoxide)ruthenium(II) reacts with AsPh₃ AsMePh₂, AsMe₂Ph and SbPh₃ in ethanolic hydrochloric acid solution to yield the complexes RuCl₂(DMSO)₂(AsPh₃)₂, RuCl₂(DMSO) L₂ (L = AsMePh₂, AsMe₂Ph, SbPh₃) respectively. The treatment of ruthenium(II) blue solution with AsMePh₂, AsMe₂Ph and SbPh₃ in alcohol resulted in the formation of the complexes; RuCl₂L₃ (L = AsMePh₂, AsMe₂Ph and SbPh₂), respectively. The reaction of RuCl₂(DMSO)₄ with the bidentate ligands 1,2 bis (diphenylarsino)methane (DPAM), 1,2 bis(diphenylarsino)ethane (DPAE) and 1,2 bis (diphenylphosphino)methane (DPPM). 1,2 bis(diphenylphosphino)ethane (DPPE), in ethanol gave the complexes RuCl₂(DPAM)₂, RuCl₂(DPAE)₂, RuCl₂ (DPPM)₂ RuCl₂(DPPE)₂, respectively. The complexes thus obtained undergo reaction with carbon monoxide, hydrogen, molecular nitrogen and nitric oxide to yield a variety of mixed ligand complexes.     

Hetarylpyrazoles. IV. Synthesis and reactions of 1,5′-bipyrazoles

A number of 1, 5′-bipyrazoles were obtained from the condensation of pyrazol-5-ylhydrazine and 1, 3-dicarbonyl compounds. Electrophilic substitution reactions of these 1, 5′-bipyrazoles occur at the four position of the pyrazole ring.     

Spectrophotometric Quantitation of Fluoxetine Hydrochloride Using Benzoyl Peroxide and Potassium Iodide

 Fluoxetine hydrochloride reacts with benzoyl peroxide and potassium iodide, after heating for 1 min at 30 °C, to give a blue colour having maximum absorbance at 570 nm. The reaction is selective for fluoxetine with 0.01 mg/mL as visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s law from 0.1 mg/10 mL to 2.0 mg/10 mL of fluoxetine and the relative standard deviation is 0.68%. The qualitative assessment of tolerable amounts of other drugs is also studied. Received September 21, 1998. Revision September 10, 1999.