Thioacetamides

For example, with thioacetamide prepared in situ in dioxane solution at 45 C, Cottet and Metzger (578) prepared the 4-methylthiazole (3), R] = Me, in 39% yield, while Erlenmeyer et al. (285) obtained a similar result in benzene and acetic anhydride. 

Aromatic thioamides can be prepared as described in the literature by different ways, either by S -> O exchange between the corresponding benzamides and phosphorus pentasulfide in pyridine solution in the presence of triethylamine (65, 646) as strong base, or by action of H2S on the appropriate nitrile with pyridine and triethylamine solvents using the method of Fairfull et al. (34, 374, 503). In this reaction, thioacetamide in acidic medium can also be used as a H2S generator with dimethylform-amide as the solvent (485). 

For example, by refluxing thioacetamide with l-phenyl-2-chloro-2,3-epoxybutane (33), Rj = Me, Rj = CH,Ph, in alcohol solution for 17 hr, 2,4-dimethyl 5-benzylthiazole was obtained (10), Rj = R2 = Me, R3 = CH,Ph. This product was found identical to that obtained from 4-phenyl-3-chloro-2 -butahone. 

Thiazoles with Heterocyouc Substituents. Thiazoles with heterocyclic substituents in the 2- or 4-position have been synthesized (Table II-9). Thus thioacetamide (or its a-substituted derivatives) react with bromomethyl heteroarylketones under reflux in alcohol to give the corresponding 2-methyl-4-heteroarylthiazoles heteroaryl groups in the 4-position were 2 -thienyl (213, 692) a-pyrrolyl and 3-method derivatives... 

Benzothia20ly]bromomethy] ketone (57) reacts with thioacetamide to give 2-methyl-4-(2-benzothiazolyI)thiazole (58) in 56% yield (468) (Scheme 26). Phenanthro[3,4d]thiazoles were also prepared from 3-phenanthrenylamine (726). 

Thiazole carboxylic acid hydrazides were prepared in a similar way (444, 445). Thus by refluxing thioacetamide or thiobenzamide with y-bromoaceto acetic ester arylhydrazones (83) for several hours in alcohol the 4-carboxythiazole derivatives (84) listed in Table II-ll were obtained (Scheme 36) (656). This reaction is presumed to proceed via dehydration of the intermediate, thiazoline-S-oxide. 

Thioacetamide [62-55-5] M 75.1, m 112-113 , pK 13.4, Crystd from absolute diethyl ether or benzene. Dried at 70° in vacuum and stored over P2O5 at 0° under nitrogen. [Develops an obnoxious odour on storage, and absorption at 269nm decreases, hence it should be freshly crystd before use). 

Acute Liver Damage Several compounds (e.g., dimethyl iiitrosoamine, carbon tetrachloride, and thioacetamide) cause necrosis of hepatocytes by inhibiting pro tein syndiesis at the translational level, i.e., by inhibiting the addition of new amino adds into the protein chain being sjTithetized. This is not, however, the only mechanism. Ethioiiine is a compound which inhibits protein synthesis bur doe not induce... 

Reaction of thioacetamide with benzaldehyde in ethanol, NaOH gave 783 that upon electrochemical oxidation afforded acrylonitrile derivative 785 together with the thiadiazoloquinoline derivative 784 (82MI199) (Scheme 137). 

Samal et al. [25] reported that Ce(IV) ion coupled with an amide, such as thioacetamide, succinamide, acetamide, and formamide, could initiate acrylonitrile (AN) polymerization in aqueous solution. Feng et al. [3] for the first time thoroughly investigated the structural effect of amide on AAM polymerization using Ce(IV) ion, ceric ammonium nitrate (CAN) as an initiator. They found that only acetanilide (AA) and formanilide (FA) promote the polymerization and remarkably enhance Rp. The others such as formamide, N,N-dimethylformamide (DMF), N-butylacetamide, and N-cyclohexylacetamide only slightly affect the rate of polymerization. This can be shown by the relative rate (/ r), i.e., the rate of AAM polymerization initiated with ceric ion-amide divided by the rate of polymerization initiated with ceric ion alone. Rr for CAN-anilide system is approximately 2.5, and the others range from 1.04-1.11. 

This transformation can also be carried out under solvent-free conditions in a domestic oven using acidic alumina and ammoniiun acetate, with or without a primary amine, to give 2,4,5-trisubstituted or 1,2,4,5-tetrasubstituted imidazoles, respectively (Scheme 15A) [69]. The automated microwave-assisted synthesis of a library of 2,4,5-triarylimidazoles from the corresponding keto-oxime has been carried out by irradiation at 200 ° C in acetic acid in the presence of ammonium acetate (Scheme 15B) [70]. Under these conditions, thermally induced in situ N - O reduction occurs upon microwave irradiation, to give a diverse set of trisubstituted imidazoles in moderate yield. Parallel synthesis of a 24-membered library of substituted 4(5)-sulfanyl-lff-imidazoles 40 has been achieved by adding an alkyl bromide and base to the reaction of a 2-oxo-thioacetamide, aldehyde and ammonium acetate (Scheme 15C) [71]. Under microwave-assisted conditions, library generation time was dramatically re-... 

Yamaguchi K, YoshidaT, Lincot D, MinouraH (2003) Mechanistic study of chemical deposition of ZnS thin films from aqueous solutions containing zinc acetate and thioacetamide by comparison with homogeneous precipitation. J Phys Chem B 107 387-397... 

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