1.2- Dithiol-3-imines, reaction with

Amino-l,2-dithiolium salts are obtained from either / -oxocarbox-amides or ) -oxocarbonitriles by reaction with phosphorus penta-sulfide, followed by addition of perchloric acid (Scheme 6). These cations, which may also be considered as iminium salts, are deprotonated to the corresponding l,2-dithiol-3-imine by ammonia. ... 

The reaction of l,2-dithiole-3-thiones with chloramine-T results in formation of analogous nitrogen compounds (e.g., 160), which may lose the exocyclic sulfur atom to form 161.220 Other N-chloroamines have been used.22 1,222 The chemistry of these imines has been studied.223 230... 

Isoxazoles possess suitable three-carbon units for conversion to the 1,2-dithiole skeleton. Thus, 5-phenylisoxazole (150) is thionated to 5-phenyl-l,2-dithiole-3-thione (151) <58AC(R)577>, and isoxa-zoline-3-thiones (152) form l,2-dithiole-3-imines by reaction with hydrogen sulfide <80CPB487>. 

However, definitive evidence for the existence of the title compounds has been given by Tamagaki and Oae, who recently reported the isolation of the compounds (112), obtained from the reaction of l,2-dithiole-3-thiones with bis(toluene-p-sulphonyl)diazomethane. The reaction of l,2-dithiole-3-thiones with Chloramine T produced thiocarbonyl imines (113) in a similar manner. ... 

Carbon nucleophiles may react at the sulfur-sulfur bond, or at C-3. Thus Grignard reagents react with monocyclic dithiol-3-ones (3a) and -3-imines (3c) at S-2 (74LA1261,73LA247). The product (84) of reaction of a Grignard reagent with benzo-1,2-dithiol-3-one (77a) (74T4113) could be alternately formed by attack at S-2, at C-3 or at C-5. Phosphonium ylides or other stabilized carbanions react at the 3-position of dithiol-ones... 

The products from the reaction of aryl amines with the l,2-dithiole-3-thione-Br2 complex have been described both as imines (83)139,140 and as isothiazolin-5-thiones (84).141 142... 

The reactions of alkynes, alkynoic esters, ynamines, and dehydrobenzene with l,2-dithiole-3-thiones (2b), and occasionally l,2-dithiol-3-imines (12c), has been extensively studied <82AHC(3i)63>. The initial products for thiones are 3-thioacylmethylene-l,3-dithioles or thiazoles (111), which can react further to form di- or tri- adducts (113) and (114) respectively. Other rearrangements can give trithiapentalenes (6). Thials, formed from reactions of 5-unsubstituted-l,2-dithiole-3-thiones, can dimerize to products (112) with loss of sulfur (Scheme 14). Similar types of reactions have been observed with l,2-dithiole-3-thiones (2b) reacting with alkenes and ketenes, especially under... 

Reactions of 3-(methylsulfanyl)-l,4,2-dithiazines with certain electrophiles give 2-amino-l,3-dithiolium cations. Thus, in 48% hydriodic acid at 40 °C, 3-(methylsulfanyl)-5,6-diphenyl-(or 5,6-tetramethylene)-l,4,2-dithiazine are converted to the corresponding 2-amino-1,3-dithioli-um iodides 3 acetyl chloride at room temperature gives Af-acetyl-l,3-dithiol-2-imines 4.1... 

The reaction of isothiazolium salts with sulphur in hot pyridine has been studied in detail. If the nitrogen atom carries an aryl substituent, the products can include l,2-dithiole-3-imines. 2-Alkylisothiazolium salts lacking a substituent in the 3-position react with aqueous hydrogen sulphide to... 

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