R. K. Ismagilov

Synthesis and oxidation of (4-hydroxy-3,5-di- tert -butylphenyl)-methanebis[diethyl(diphenyl)phosphine oxides]

The phosphorylated sterically hindered phenols and methylenequinones are potential inhibitors of oxidation of organic materials like polymers, petrochemical products, and biological systems [1–2]. In extension of studying the reaction of geminal polyhalides with aprotic nucleophilic reagents [3–5] we studied the reaction of 4-hydroxy-3,5-di-tert-butylbenzal chloride I with diethyl and diphenyl chlorophosphines. The reaction of dichloride I with diethyl chlorophosphine was found to proceed at keeping the hexane solution of reagents taken in the ratio 1:2 at room temperature for 24 h. The reaction of dichloride I with diphenyl chlorophosphine requires the heating of the reagents mixture at 100–110°С for 3 h. Adducts III form in high yields as colorless hygroscopic viscous products, weakly fuming in the air. According to the Р NMR spectra, compounds IIIa (δP 69.36 ppm) and IIIb (δP 71.02 ppm) have phosphonium structure in keeping with the literature data [6, 7]. The treatment of adducts IIIa and IIIb with anhydrous ethanol followed by evaporating of the solvents in a vacuum gives the corresponding bisphosphine oxides IV. DOI: 10.1134/S1070363210030278

Synthesis and properties of [(4-Hydroxy-3,5-di-tert-butylphenyl)-chloromethanediphenylphosphine oxide

Received March 23, 2012 LETTERS TO THE EDITOR ISSN 1070-3632, Russian Journal of General Chemistry, 2012, Vol. 82, No. 9, pp. 1587–1589.

Synthesis and Properties of Some Sulfur-Containing Derivatives of Phosphorylated Sterically Hindered Phenols

The addition of thioacetic acid to 2,6-di-tert-butyl-4-(phosphorylmethylidene)cyclohexa-2,5-dien-1-ones has been accomplished for the first time. The resulting adduct is readily hydrolyzed with hydrazine hydrate to give 2,6-di-tert-butyl-4-[phosphoryl(sulfanyl)methyl]phenols, and the latter reacted with the initial quinomethanes, yielding 4,4′-[sulfanediylbis(phosphorylmethylene)]bis(2,6-di-tert-butylphenols).

Reactions of phosphorylated 2,6-di- tert -butyl-4-methylidenecyclohexa-2,5-dien-1-ones with aliphatic, aromatic, and heteroaromatic thiols

The addition of alkanethiols, benzenethiol, and hetarenethiols to phosphorylated quinomethanes afforded P,S- and N,P,S-containing polyfunctional organic compounds as potential bactericidal agents.

On the reaction of 4-chloromethylene-2,6-di-tert-buthylcyclohexa- 2,5-dien-1-one with P(III) acids esters

Proceeding with investigations on reactions of organic halides with aprotic reagents [1, 2], we pioneered in studying reactions of 4-chloromethylene2,6-di-tert-butylcyclohexa-2,6-dien-1-one I (chloromethylenequinone) with P(III) acids esters, such as triethyl phosphite IIа and ethyl diphenylphosphinite IIb. Phosphorylated ylides VII were established to be the main products of the reaction of chloromethylenequinone I with esters II in a 1:2 ratio. We suppose that ylide VII is formed by the following two-stage scheme: DOI: 10.1134/S1070363209010307

Addition of phthalimide and acetone to phosphorylated methylene quinones

New method for synthesis of phosphorylated methylene quinones via bromination of the sterically hindered phenol [prepared via benzylation of secondary chlorophosphines with 4-(methoxymethyl)-2,6-di-tert-butylphenol] with N-bromosuccinimide followed by dehydrobromination with trimethyl orthoformate has been developed. Tertiary phosphine oxides containing the fragment of sterically hindered phenol and amine or acetonyl group have been synthesized for the first time in the reaction of phosphorylated methylene quinones with N- and C-nucleophiles.

Study of the reaction of 4-chloromethylene-2,6-di-tert-butylcyclohexa-2,5-dien-1-one with the P(III) acids esters

The main stable products of the reactions 4-chloromethylene-2,6-di-tert-butylcyclohexa-2,5-dien-1-one with triethyl phosphite and ethyl diphenylphosphinite are the phosphorylated phosphorus ylides, 3,3′,5,5′-tetra-tert-butylstilbenequinone, and biphosphorylated sterically hindered phenols.

Reactions of 4-hydroxy-3,5-di-tert-butylbenzylidene chloride with aminals

We found that this bond is also cleaved with 4-hydroxy-3,5-di-tert-butylbenzylidene chloride I. Reactions of I with aminals II occur with a heat release upon mixing the reactants (neat or in solvents such as ether or hexane). Irrespective of the structure of the aminal and reactant ratio, gem-dichloride I undergoes dehydrochlorination and dechloroamination with the formation of 4-(dialkylaminoor piperidino)methylene-3,5-di-tert-butylcyclohexa-2,5-dienones III. The dialkylamine formed in the dehydrochlorination step, as found in additional experiments, further reacts with I to form salt V [3, 4]. When the reaction of I with IIa was performed in diethyl ether, a crystalline mass consisting of IVa and Va was obtained. By its treatment with ethyl diphenylphosphinite, we obtained individual products: (dimethylamino)methyldiphenylphosphine oxide VI and dimethylammonium chloride Va.