T. D. Churkina

Investigation of the reaction of phenyl radicals with phenyl esters of thiocabboxylic acids

Conclusions1.Phenyl radicals add to the phenyl esters of thiocarboxylic acids (R=Ph, Ph2CH, PhCH2) at the sulfur atom of the C=S group with the formation of radical-adducts of the type, which were identified by ESR using a spin trap technique.2.The radical-adduct Ph2 is converted into the O,S-bis-phenylacetal of diphenylketene and the phenyl ester of diphenylthioacetic acid while the radical-adduct is converted into the phenyl ester of thiobenzoic acid and diphenyldisulfide.

Rearrangement of radicals with 1,2-migration of chlorine during phenylation of ethyl tri and dichlorothionoacetates

Conclusions1.The addition of phenyl radicals, generated by the decomposition of nitrosoacetanilide or benzoyl peroxide, to ethyl trichlorothionoacetate proceeds with the formation of the radical adducts CCl3C(SPh)OEt (B radicals). The latter rearrange with 1,2-migration of Cl to the CCl2C(Cl)(SPh)OEt radicals, which were identified by EPR using the spin trap technique.2.Phenylation of ethyl dichlorothionoacetate followed by rearrangement of the CHCl2C (SPh)OEt radical adducts to the CHClC(Cl)(SPh)OEt takes place only when benzoyl peroxide is the source of phenyl radicals, Ph·. In the case of nitrosoacetanilide the primary radicals are stabilized by oxidation to form ethyl dichloroacetate and Ph2S2.

Radical reactions of butyl mercaptan with vinyl and allyl acetates

ConclusionsThe reactions of vinyl acetate and allyl acetate with butyl mercaptan in the presence of tert-butyl peroxide and Mn2(CO)10 lead to an adduct. Acetaldehyde, butyl thioacetate, and the dibutylmercaptal of acetaldehyde are also formed in the case of Mn2(CO)10.

Reactions of acrylic monomers with mercaptans in the presence of metal carbonyls or peroxides

Conclusions1.In the telomerization of acrylic monomers with mercaptans, the change from initiation by peroxides to initiation by metal complexes leads to a significant change in the nature of the distribution of the homologs in favor of the adduct.2.The distribution of the telomer homologs in reactions of n-butyl mercaptan with acrylonitrile, methyl acrylate, and methyl methacrylate with initiation by carbonyls of Mn, Mo, and Cr, in contrast to peroxide initiation, is practically insensitive to a change in the ratio of the reagents.

Reaction of butyl mercaptan with phenyl esters of dithiocarboxylic acids

ConclusionsThe reaction of butyl mercaptan with phenyl dithioisobutyrate in the presence of tertbutyl peroxide proceeds with the addition of butylthio radicals at the carbon atom of the C=S bond.

REACTION OF PHENYLDITHIOBENZOATE WITH p-TOLYL RADICALS AND WAYS OF STABILIZATION OF BIS(ARYLTHIO)ARYLMETHYL RADICALS

Conclusions1.Upon reaction of N-nirosoacet-p-toluidide with phenyl-dithiobenzoate, together with S-aryl esters of thiobenzoic acid and diaryldisulfides, triarylorthothiobenzoates Ph-C(SAr)3 (Ar=Ph, Tol) are formed, the structure of which was proved by x-ray structural analysis and PMR.2.Intermediate adduct-radicals formed in the reaction do not dimerize and are subjected to oxidation followed by fragmentation and recombination with ArS radicals.

Radical arylation of esters of dithiocarboxylic acids

Conclusions1.The interaction of N-nitrosoaceto-p-toluidide (NAT) with the phenyl esters of diphenyldithioacetic, phenyldithioacetic, and dithioisobutyric acids proceeds with the practically complete addition of the generated tolyl radicals to the thiocarbonyl group of the compounds indicated.2.The main products of the reactions under consideration are the phenyl tolyl mercaptals of the corresponding ketenes and also the S-phenyl and the S-tolyl esters of the corresponding thiol acids and the diaryldisulfides. The formation of these products is explained by the competition of different routes for the stabilization of the adduct-radicals R1R2CHC(SPh)STol which are formed as intermediates in the arylation.

Reaction of phenyl dithiobenzoate and N-butylthioacetamide with N-nitrosoacetanilides

Conclusions1.The reaction of phenyl dithiobenzoate with N-nitroso-p-toluidine proceeds with complete capture of the tolyl radicals formed in the decomposition of NAT by the thione group. The major reaction product is 1,2-bisphenylthio-1,2-bistolylthio-1,2-diphenylethane, which indicates the intermediate formation of the radical-adduct PhĊ(SPh)STol (A).2.A side-reaction leading to the formation of S-tolyl and S-phenyl thiolbenzoates and diaryl disulfides is explained by the oxidation of radical-adduct A and subsequent fragmentation due to loss of an ArS. radical.3.The reaction of N-butylthioacetamide with N-nitrosoacetanilide involves oxidation of radical-adduct MeĊ(SPh)NHBu and subsequent fragmentation, which is the major pathway of the reaction leading to the formation of N-butylacetamide, diphenyl disulfide, and diphenyl sulfide.

Reduction of trichloromethyl group to the dichloromethyl group by thiols in the presence of metal carbonyls

Conclusions1.The carbonyls Fe(CO)5, Mn2(CO)10, Mo(CO)6, and W(CO)6 initiate the selective reduction of the CC13 group to the CHCl2 group by thiols. The reduction systems thiol + Mn, Mo, and W carbonyls have been used for the first time.2.The reduction of CCl3(CO2)nCl (n=4, 6, 8), CCl3(CH2)5CH3, CCl3CH2CH(CH3)CH2CHCl-CH3, and CCl3CHC1(CH2)3Cl showed that Fe(CO)5 and Mn2(CO)10 were the most effective initiators.

Free-radical reactions of 2,2-bis(n-butylthio)-4-pentanone and 2-(n-butylthio)-2-pentene-4-one

Conclusions1.The reaction of 2,2-bis(n-butylthio)-4-pentanone with tert-butyl peroxide (TBP) forms the radicals CH3COCH2C(SBu)2CH2 and CH3COCHC(SBu)2CH3, which rearrange with 1,2-migration of the BuS group to form 1,2-bis(n-butylthio)-4-pentanone and 2,3-bis(n-butylthio)-4-pentanone.2.The addition of n-butanethiol to 2-n-butylthio-2-pentene-4-one in the presence of TBP at 130°C forms 2,2-bis(n-butylthio)-4-pentanone and 1,2-bis(n-butylthio)-4-pentanone. Formation of the 1,2-bis-sulfide is explained by allylic isomerization of 2-n-butylthio-2-penten-4-one, with migration of a hydrogen atom.