Thiocarboxylic acid amides

The reaction of thiocarboxylic acid amides 573 with carbodiimides affords 1,2,4-ttiazoles... 

No aminothiophenones can be obtained by photorearrangement of JV-aryl amides of thiocarboxylic acids. The formation of 2-ethoxybenzthiazole (143) by oxidative photodehydrogenation of 142 is of some interest.11 Similarly, 2-phenylbenzthiazole originates by photocyclization of thiobenzanilide in the presence of oxygen."... 

The reaction of thioethers with ethyleneirnine in the presence of acid yields sulfonium compounds. The reaction is reversible under alkaline conditions (125). Compounds in which double-bonded sulfur can exist in tautomerism with a form having a free SH group, such as thiourea (126,127), thiocarboxylic acids (128), and thiophosphates (129), react to give aminoalkylated products. The (1 ammoetliyl thiocarboxylate rearranges to give the amide. 

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... 

Fukuyama [5] obtained the thioester 35 from the reaction of the thiocarboxylic acid anion 34 with the / -lactone compound 17. After acidic deprotection of the Boc group, the thiazoline ring is successfully closed in benzene under Dean-Stark conditions (35 —> 33) in yields between 60 and 80 %. Ehrler [6] and Pattenden [7] choose a more classical way. They close the thiazoline ring by condensation of the aminothiol hydrochloride 5 x HCl with a nitrile. The yields are generally modest (45 and 55 %) except in one case [6]. Installation of the necessary nitrile function hinders its repetitive use, as this procedure causes a considerable loss of material. Heathcock [8] and Ehrler [6 choose the thiol-amide 37 as a key compound. Titanium tetra-... 

Prepn. from N,N-disubst. carboxylic acid amides—Thiocarboxylic acid esters Dithiocarboxylic, thiolic, and thionocarboxylic acid esters—Ring closures to heterocyclics s. 19, 628 a-chlorimmonium chlorides cf. M. Grdini6 and V. Hahn, J. Org. Chem. 30, 2381 (1965)... 

The classical Ugi four-component reaction (U-4CR) originally described by Ugi et al. [1] consists in the reaction of a primary amine, a carbonyl compound (aldehyde or ketone), an isocyanide, and a carboxylic acid to afford a-acylamino amides 36 (Scheme 7.14) [31, 32], Rapidly, other components or adducts were found to give the Ugi-4CR—that is, ammonia, hydroxylamine, or hydrazine as amine component or thiosulfates [33], thiocarboxylic acids [34], isothiocyanic acids [35], hydrazoic acid [36], or carbonic acid monoesters... 

The required imidoyl chlorides can also be prepared in situ from nitriles and hydrogen chloride. For example, Ishikawa ( ) obtained thio amides in the reaction of nitriles with hydrogen chloride and thiocarboxylic S-acids CII. 

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