Amines carboxylic acid thioamides

Carboxylic acid thioamides from amines s. 4, 547 CH2NH2 CSNHs... 

Acylaminosulfenium salts S-Acylhydrosulfamines N-Acylsulfenamides N-Acylsulfilimines 1 - Alkoxy-1 -alkylthio-1 -amines 1 - Alkylthio-1 -oximes S-Aminosulfoxonium ylids Carboxylic acid thioamide S-oxides... 

A soln. of Na-methoxide in methanol added dropwise to a soln. of Se-phenyl 4-methylbenzenecarboselenothioate in ether, and stirred at ca. 20° for 2 h O-methyl 4-methylbenzenecarbothioate. Y 86%. F.e. and prepn. startg. m., also carboxylic acid thioamides from amines, s. S. Kato et al., Bull. Chem. Soc. Japan 61, 3931-42 (1988). 

Prim, amines from carboxylic acid thioamides s. 17, 77 CSNH2 CH2NH2... 

Prim, amines from carboxylic acid thioamides... 

A further improvement is embodied in the Klndler variation of the Willgerodt reaction this consists in heating the ketone with approximately equal amounts of sulphur and a dry amine instead of aqueous ammonium polysulphide. The principal product is a thioamide, and hydrolysis with acid or alkali affords the carboxylic acid, usually in good yield. 

The reaction of alcohols with CO was catalyzed by Pd compounds, iodides and/or bromides, and amides (or thioamides). Thus, MeOH was carbonylated in the presence of Pd acetate, NiCl2, tV-methylpyrrolidone, Mel, and Lil to give HOAc. AcOH is prepared by the reaction of MeOH with CO in the presence of a catalyst system comprising a Pd compound, an ionic Br or I compound other than HBr or HI, a sulfone or sulfoxide, and, in some cases, a Ni compound and a phosphine oxide or a phosphinic acid.60 Palladium(II) salts catalyze the carbonylation of methyl iodide in methanol to methyl acetate in the presence of an excess of iodide, even without amine or phosphine co-ligands platinum(II) salts are less effective.61 A novel Pd11 complex (13) is a highly efficient catalyst for the carbonylation of organic alcohols and alkenes to carboxylic acids/esters.62... 

Electrophilic substitution of the ring hydrogen atom in 1,3,4-oxadiazoles is uncommon. In contrast, several reactions of electrophiles with C-linked substituents of 1,3,4-oxadiazole have been reported. 2,5-Diaryl-l,3,4-oxadiazoles are bromi-nated and nitrated on aryl substituents. Oxidation of 2,5-ditolyl-l,3,4-oxadiazole afforded the corresponding dialdehydes or dicarboxylic acids. 2-Methyl-5-phenyl-l,3,4-oxadiazole treated with butyllithium and then with isoamyl nitrite yielded the oxime of 5-phenyl-l,3,4-oxadiazol-2-carbaldehyde. 2-Chloromethyl-5-phenyl-l,3,4-oxadiazole under the action of sulfur and methyl iodide followed by amines affords the respective thioamides. 2-Chloromethyl-5-methyl-l,3,4-oxadia-zole and triethyl phosphite gave a product, which underwent a Wittig reation with aromatic aldehydes to form alkenes. Alkyl l,3,4-oxadiazole-2-carboxylates undergo typical reactions with ammonia, amines, and hydrazines to afford amides or hydrazides. It has been shown that 5-amino-l,3,4-oxadiazole-2-carboxylic acids and their esters decarboxylate. 

Carboxylic acid, amine and O/7-dicihyl dithiophosphoric acid (3 equiv.) have been refluxed in toluene. This one-pot reaction yields the corresponding secondary or tertiary thioamides (Scheme ll).32... 

With primary and secondary amines, the aminolysis of a trifluoromethyl group to a carbonitrile group is not possible nevertheless, under these reaction conditions, analogs of carboxylic acids, c.g. amidines,51,52 amides29,53 - 55 or thioamides,56 are formed. 

In 1996 we performed a classical U-4CR of primary amines, aldehydes and isocyanides, but instead of using carboxylic acids we employed thiocarboxylic acids [17]. The reaction leads highly chemoselectively to a-aminoacyl thioamides and no trace of a-aminothioacyl amides is found. This finding is not noteworthy per se and... 

Contrary to carboxylic acids which, under normal conditions, only give salts with amines, dithiocarboxylic acids, RCS2H, are quite reactive in nucleophilic displacement reactions. However, the compounds are unpleasant to handle and, due to their limited stability, often give only low yields of thioamides in the reaction with amines.The approach was successfully employed in the synthesis of thiobenzoyl azolides, e. g. in the formation of (7) according to equation (4). °... 

An important modification of the reaction introduced by Kindler consists in heating the ketone with an equivalent amount of sulfur and an amine which is resistant to oxidation the product is a thioamide which on hydrolysis yields the carboxylic acid. Morpholine is a particularly favorable amine component for this variation see Morpholine. 

The Kindler variation, - which promises to be more useful than the original Willgerodt procedure, consists in heating the ketone with approximately equimolecular amounts of sulfur and a dry amine instead of aqueous ammonium polysulfide. A thioamide is formed as the principal product and on hydrolysis with acid or alkali affords the carboxylic acid, usually in good yield. Generally a secondary aliphatic amine but sometimes a primary amine or even anhydrous ammonia is used the development of a method for the electrolytic reduction of the thioamides to amines extended the usefulness of the reaction as a new route to the synthesis of many important nitrogen bases. Early descriptions of this... 

It is of interest to note the behavior of molecules containing other functional groups. Carbinols form amides at somewhat higher tanpera-tures than the corresponding ketones, probably by way of unsaturated intermediates. Aldehydes are converted into the corresponding carboxylic acid amides when heated with aqueous ammonium polysulfide, > and they form substituted thioamides under conditions of the Kindler procedure. Aldimines likewise are converted to acid derivatives. Two imineS derived from methyl ketones and methylamine are reported to react with sulfur to form N-methylarylthioacetamides in a manner analogous to the reaction of methyl ketones in the presence of the amine. 

Certain malononitrile, ethyl cyanoacetate, alkoxide and thiophenolate anions behave similarly and give the requisite acrylic acid derivatives or tautomers thereoF Moreover, the reaction of various carboxylates, amides, amines (but not ammonia, see below) thioamides, ynamines, pyridines and j5-acylenamines give products which are rationalized in terms of an initial 1,2-addition . ... 

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