Synthesis, structure, and characteristics of 1,2-dichlorovinyl alkyl ketones

Abstract

A method of alkyl 1,2-dichlorovinyl ketones preparation from acyl halides and 1,2-dichloroethylene was developed. The configurational equilibrium and electronic structure of alkyl 1,2-dichlorovinyl ketones was investigated by IR, 1 H and 13 C NMR spectroscopy, by measuring dipole moments, and by quantum-chemical calculations using methods RHF and B3LYP in the basis 6-311++ G (d,p). Alkyl 1,2-dichlorovinyl ketones are stable in the Z,s-cis-configuration where the olefin proton is involved into an intramolecular hydrogen bond with the oxygen of the carbonyl group. Reaction of 1,2-dichlorovinyl ketones with alkylhydrazines afforded 1-alkyl-3-alkyl-4-chloropyrazoles. The reaction of alkyl 1,2-dichlorovinyl ketones with 1,1-dimethylhydrazine involved dehydrochlorination and afforded 1,1-dimethylhydrazinium hydrochloride and a mixture of compounds with uncertain structure. B +&O $ON&2&&O &+&O ,9 B 9, , B ,,,Under conditions used in the synthesis of dichloromethyl 1,2-dichlorovinyl ketone [3] but applying the commercially produced mixture of cis-and trans-1,2dichloroethenes methyl and propyl 1,2-dichlorovinyl ketones were obtained in the yield not exceeding 24%. Alk = Me (I, IV), Et (II, V), Pr (III, VI).

Synthesis of Bis(2-acyl-2-chlorovinyl) Sulfides

“…1 Bis(2-chloro-3-oxo-1-pentenyl) sulfide (II). The mixture was stirred for 6 h at room temperature and poured into water.…”

“…1 The 1 H and 13 C NMR spectra were recorded on a Bruker DPX-400 spectrometer at 400.13 and 100.61 MHz, respectively, using HMDS as internal reference. Compound II was synthesized as described above for I (method c) from 0.75 g (0.01 mol) of thioacetamide and 1.53 g (0.01 mol) of ethyl 1,2-dichlorovinyl ketone.…”