V. G. Rozinov

Phosphorylation of C-alkenylsubstituted pyrazoles with phosphorus pentachloride

The reaction of phosphorus pentachloride with styrenes affords unsaturated organophosphorus compounds in which the phosphorus chloride substituent is attached to the carbon atom of the double bond [1]. NVinylsubstituted azoles are also phosphorylated at the double bond [2–3]. Phosphorylation of С-alkenylazoles with phosphorus pentachloride was not studied until now. The presence in the azole cycles the “pyridine” nitrogen atoms with enhanced nucleophilicity could direct the attack of phosphorus pentachloride to the heterocycle rather than to the double bond of Сvinylazoles to give donor–acceptor complexes. Indeed, the reaction of phosphorus pentachloride with 1-allyl3,5-dimethylpyrazole led to formation of the donor– acceptor complex I. DOI: 10.1134/S1070363209060358

Reaction of phosphorus pentachloride with N-vinylimidazole and N-vinylbenzimidazole

Earlier, we have found that N-vinylpyrazoles are phosphorylated with phosphorus pentachloride at the double bond to give rise to unsaturated organophosphorus compounds [1]. N-Vinylimidazoles contain-ing in the ring highly basic separated nitrogen atoms of the pyridine type react with phosphorus pentachloride in a different manner. In these reactions, the first and foremost are the donor–acceptor interactions. N-Vinylimidazole I reacts with phosphorus pentachloride (even in the excess of the latter) to give the donor– acceptor complex III with participation of the pyridinium nitrogen atom. As a result, the electron–acceptor properties of the ring increase and the nucleophilicity of the N-vinyl group decreases hampering its phosphorylation. The treatment of azole I with the solution of phosphorus pentachloride in benzene saturated with hydrogen chloride affords complex compound IV containing the protonated nitrogen atom in the 3 position.

New methods of synthesis of phosphoryl and thiophosphoryl halides from organylchlorophosphonium hexachlorophosphorates

A new method of synthesis of phosphonic and thiophosphonic chlorides is offered, based on treatment of acyclic and cyclic organylchlorophosphonium hexachlorophosphorates with dimethylformamide, dimethylacetamide, or dimethylthioacetamide. The method involves no formation of phosphoryl chloride and thiophosphoryl chloride, which facilitates isolation of the target products. The reactions of alkenylchlorophosphonium hexachlorophosphorates with amides and thioamides results in incorporation of the PCl6- anion into an insoluble chloroiminium salt which is easily separated by filtration. Removal of the solvent leaves almost pure phosphonic or thiophosphonic chlorides.

35Cl NQR of 1,5,2-Diazaphosphorine Derivatives

Abstract NQR frequencies and asymmetry parameters (η) of 35Cl chlorine-containing 1,5,2-diazaphosphorine derivatives are reported and discussed. NMDO calculations with total optimization of geometry have been carried out. The νcal and ηcal values, calculated by means of the Townes and Dailey theory, correlate well with the experimenal data.

Reaction of divinyl ether with phosphorus pentachloride

It is known that divinyl sulfides are phosphorylated by phosphorus pentachloride with the formation of 1,4-thiaphosphorin derivatives. The authors have found that divinyl ether is phosphorylated by phosphorus pentachloride in a benzene medium with the formation of 4,4-dichloro-4H-1,4-oxaphosphorin-4-ium hexachlorophosphate; the process goes analogously to the phosphorylation of divinyl sulfide. The /sup 1/H, /sup 31/P, and /sup 13/C NMR spectra were recorded on a Bruker WP-200SY spectrometer at room temperature. Stabilization was effected by the signal of deuterium in CDCl/sub 3/. The /sup 31/P signals were recorded relative to 85% H/sub 3/PO/sub 4/ as external standard.

1,3,4-Diazaphosphorine from n-acetylurea

In continuation of the authors study of phosphorylation of acetamides we found that N-acetylurea reacts readily with both a solution and with a dispersion of PCl/sub 5/ in benzene to form 2,6-dichloro-1,3,4-diazaphosphorine (I), a crystalline compound which is stable during distillation in vacuo, but which hydrolyzes in air. Compound (I) is soluble in benzene, diethyl ether, and chloroform. The elemental analysis and /sup 31/P, /sup 1/H, and /sup 13/C NMR and /sup 35/Cl NQR spectroscopy data conform well with the proposed structure of compound (I).

Synthesis of 1,3,4-thiadiazaphospholes from 1-phenoxy-2-thiocyanatoethene

1-Phenoxy-2-thiocyanatoethene undergoes reaction with phosphorus pentachloride with the participation of two reaction centers, vinyl and thiocyanate groups, to form a phosphorus-containing heterocycle, a derivative of 1,3,4-thiazaphosph-2-ole. Transformations of the phosphorylation product were studied. The /sup 1/H, /sup 31/P, and /sup 13/C NMR spectra were recorded on a WP-200SY Bruker spectrometer at room temperature. The stabilization was carried out with respect to a deuterium signal in CDCl/sub 3/. The /sup 31/P NMR signals were recorded relative to 85% H/sub 3/PO/sub 4/ as external standard (the positive values designate shift to the weak field) with a heteronuclear broadband uncoupling from protons.