Thioacyl chlorides thioacylation

R = Ph) is also formed in the reaction between diazomethane and thiobenzoyl chloride, probably via a 1,3-dipolar addition of diazomethane to the thiocarbonyl group. Similar additions have been observed by Huisgen et The reaction between thioacyl chlorides and diazo compounds was first studied by Staudinger and Siegwart.i 3 (R = Ph) has been prepared by cyclization of 11 with triethylortho-formate, and also from 2-phenyl-1,3,4-oxadiazole and phosphorus pentasulfide. ... 

Thioacyl chlorides, RCSCl, are powerful thioacylating agents as is obvious from the quantitative thiobenzoylation of the only moderately nucleophilic nitrogen in thiocarbamate (13 equation 5). However, severe limitations are the difficult accessibility of thioacyl chlorides and their thermal lability. Even if they are prepared from dithiocarboxylic acids using an improved procedure, only thioaroyl chlorides, particularly PhCSCl (12), can be handled sufficiently easily to be used in synthetic work. Thus, various azoles react with (12) to furnish /V-thiobenzoyl azolides (14) in the presence of excess azole or NEts (equation 6) a particularly clean and fast reaction is achieved if IV-silylated azoles are employed. However, considering the fact that the chloride has to be prepared from the dithiocarboxylic acid, the approach of equation (4) presents a shortcut to the products. 

In contrast to thioacyl chlorides, thiophosgene, CSCh, is readily accessible and conveniently handled making it an important reagent in the synthesis of thiocarbamoyl chlorides (15 ClCSNRa), 0-alkyl thiourethanes (ROCSNR 2), and thioureas (R2NCSNR2) (c/. Volume 6, Chapter 2.8). ... 

A stable aliphatic thioacyl chloride (44) was obtained according to equation (42) and used in alcoholysis reactions to prepare thioxo malonates (45)."° A mixture of sulfenyl chloride (46) and trisulfide (47), which does not however contain an a-oxothioacyl chloride, also yields thioxoesters on base-catalyzed reaction with methanol (equation 43). ... 

The formation of thioacyl chloride 5-oxides (chlorosulfines, 84), first reported by Wedekind and coworkers5,34, was the reaction that prompted the suggestion of this mode of addition in the first place. The proposed mechanism is shown in Scheme. 5. 

Thioacyl chlorides. Aliphatic thioacyl chlorides have been prepared for the first time by addition of hydrogen chloride at -80° to thioketenes in CFCI3. 

THIIRANES 3-Methylbenzothiazole-2-thione. 2-Thiomethyl-4,4-dimethyl-2-oxazoline. THIIRENIUM SALTS Methyl(bismethylthio)sulfonium hexachloroantimonate. THIOACYL CHLORIDES Hydrogen chloride. 

Reaction with active CH compounds. Japanese chemists have reported the oxidation of active methyl compounds to thioacyl chlorides with thionyl chloride. Examples ... 

It has been emphasized by Kato and his co-workers that di- and tri-alkyl-ammonium dithiocarboxylates are readily obtained as stable crystals, which are more useful than metal salts in the purification and preparation of derivatives. Synthesis of Thioacyl Halides.—Aromatic thioacyl chlorides, but not the unknown thioacetyl chloride, have been prepared in a convenient way, using phosgene as the chlorinating agent. ... 

Aliphatic thioacyl chlorides, e.g. Bu CH2C(S)Cl and Bu CHClC(S)Cl, can be obtained by addition of hydrogen chloride or chlorine, respectively, to the thioketen Bu CH=C=S, generated by flash pyrolysis of 4-t-butyl-l,2,3-thiadi-azoles or by direct reaction with the heated thiadiazole. The addition of hydrogen chloride to the alkynethiolate ion Bu C=CS also gives the thioacyl chloride Bu CHaC(S)Cl. Addition of thiophosgene to the enamine Mc2NC(Bu )=CHa... 

In order to elucidate the molecular structure, H n.m.r. spectra of thio-esters have been measured in numerous cases, which are not cited here. C n.m.r. spectra of thioacyl chlorides, e.g. Bu CHClC(S)Cl, and thiono-esters have also been reported. The barriers to internal rotation about the C—S bond are... 

A variety of thioamides and heterocyclic compounds containing the thiolactam grouping have been synthesized by thioacylation of amines by means of thioketens, thioacyl chlorides,ethyl thionoformate, dithio-acids 3, l(4H)-benzothiazine-4-thiones, 2,4-dithioxodihydro-... 

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