Thiophosgene preparation

Preparation. Thiophosgene forms from the reaction of carbon tetrachloride with hydrogen sulfide, sulfur, or various sulfides at elevated temperatures. Of more preparative value is the reduction of trichi oromethanesulfenyl chloride [594-42-3] by various reducing agents, eg, tin and hydrochloric acid, staimous chloride, iron and acetic acid, phosphoms, copper, sulfur dioxide with iodine catalyst, or hydrogen sulfide over charcoal or sihca gel catalyst (42,43). 

Chlorophenyl isothiocyanate has also been prepared by treating an alcoholic solution of sym-di-/)-chlorophenyl thiourea with iodine/ from ammonium -chloroplienyldithiocarbamate and lead nitrate/ (p. 72), and from the action of thiophosgene with /)-chloroaniline. ... 

Thiophosgene has been prepared in small yield by the chlorination of carbon disulfide in the presence of iodine and by the reduction of thiocarbonyl perchloride. ... 

The related thionocarbonate is prepared from thiophosgene (Pyr, DMAP, 78% yield). 

Treatment of a chiral amine with phosgene is the cheapest way to prepare symmetrical ureas [29]. Nevertheless, due to the toxicity and reactivity of that reagent, it can advantageously be replaced by triphosgene [30] or l,l -carbonyldiimidazole [31-34] or other derivatives such as l,l -carbonyldi-2(lH)-pyridinone [35]. This procedure can be extended to thiophosgene (Scheme 1) and its thio-analogues, such as l,l -thiocarbonyldi-2(lH)-pyridinone to produce thioureas [36] chiral diamines can thus be transformed into the corresponding monoureas or monothioureas. 

Bis(benzotriazol-lyl)methanethione 974 is easily prepared from thiophosgene and l-(trimethylsilyl)benzotriazole <1978JOC337>. In reactions with thiols and triethylamine, thiones 974 are converted to derivatives 973 in modest yields the main side products result from nucleophilic attacks of the thiolate anions on the thione sulfur atom to produce disulfides <2005JOC7866>. In reactions with amines, compounds 974 are smoothly converted to l-(thiocarbamoyl)benzotriazoles 975 <2004JOC2976>. Substitution of one of the benzotriazolyl groups in 974 by phenolate anions yields l-(aryloxythioacyl)benzotriazoles 978 (Scheme 161) <2005JOC7866>. 

In carbohydrate chemistry, the most described method for the preparation of saccharidic thionocarbamates involves preliminary introduction of the amine function on a partially or non-protected saccharidic template. The condensation of amino sugars with carbon disulfide or thiophosgene leads to cyclization in 1,3-oxazolidine- or l,3-oxazine-2-thiones. This reaction involves the formation of an intermediate isothiocyanate, which reacts further with a 3- or y-located hydroxyl group. The viability and facility of this process depends on the saccharidic ring size and the inherent strain. Some major rules can be put into light from the cases studied 30... 

Dichlorosulfine (50), prepared by oxidation of thiophosgene with m-chloroperbenzoic acid, is a powerful dienophile. It reacts with cyclopentadiene in pentane at —40 °C to give the cycloadduct 51 (equation 35)32. 

Symmetrical dialkyl and diaryl thioureas have been prepared in generally good yield (60-90%) from the reaction of the amine with thiophosgene, formed in situ from the catalysed reaction of carbon tetrachloride with sodium sulphide [5], Reaction with diamines yields cyclic ureas. 

The procedure given here is essentially that described previously by the submitters. -Chlorophenyl isothiocyanate has been prepared from sym-di-p-chloiophenyl thiourea with iodine in alcoholic solution, from ammonium p-chlorophenyldithio-carbamate and lead nitrate [cf. also Org. Syntheses, Coll. Vol. 1 447 (1932)], by the action of thiophosgene on />-chloroaniline and from -chloroaniline with thiocarbonyl tetrachloride in the presence of stannous chloride. ... 

Alternative precursors for the synthesis of NHCs are thiourea derivatives of type 3. The preparation of such thiones with a symmetrical substitution pattern is achieved by the reaction of a-hydroxyketones like 3-hydroxy-2-butanone with suitable 2-thiones (Fig. 3d) [31] or by reaction of a diamine with thiophosgene [32, 33]. Unsymmetrically substituted thiones 4 possessing a saturated heterocycle have also been described (Fig. 3e) [34, 35]. 

The parent 4-oxo-2-thioxopyrimidines 305 (cis, n = 1, 2 trans, n = 2 R = H), 306 cis or trans), 307 and 308 diendo and diexo) were prepared analogously to pyrimidinediones by reacting the corresponding amino ester hydrochlorides with potassium thiocyanate (89MRC959), or from alicyclic ethyl 2-isothiocyanato-l-carboxylates, obtained by the reaction of amino esters and thiophosgene with ammonia (96UP2). 

The highly explosive 5-chloro-l, 2,3,4-thiatriazole (prepared from thiophosgene and sodium azide) has been used for the preparation of 5-substituted 1,2,3,4-aminothiatriazoles and certain 5-alkoxy-thiatriazoles (Section 4.19.7). Great care should be exercised in handling any reaction product of thiophosgene and azide ion. In particular the reaction of 5-chloro-l,2,3,4-thiatriazole with azide ion yielded a product assumed to be 5-azido-l,2,3,4-thiatriazole which gave rise to explosion as a suspension in water (61J0C1644>. 

The cycloaddition of two isothiocyanate molecules, prepared by condensation of 6-methoxy-3-pyridinamine and thiophosgene, produces a new type... 

The 2-thione derivative of [l,3]dithiolo[4,5-f][l,2,5]thiadiazole 41 was prepared from the parent dichloride 163 following treatment of the intermediate disodium salt 171 with thiophosgene (Scheme 33) <1993SM(68)1914, 1997USP5703102>, while the bisthioester 103 was the precursor to the 2-one derivative 43 (Schemes 7 and 33) <1997SM(86)1871>. 

Preparation of polycyclic orthocarbonate by reaction of 2,2-dihydroxy-biphenyl with thiophosgene [187]. 

Cyclic thionocarbonates (41) can be cleaved to olefins (the Corey-Winter reaction)274 by heating with trimethyl phosphite275 or other trivalent phosphorus compounds276 or by treatment with bis(l,5-cyclooctadiene)nickeI.277 The thionocarbonates can be prepared by treatment of 1,2-diols with thiophosgene and 4-dimethyIaminopyridine (DMAP) 278... 

Isothiocyanates can be prepared from support-bound primary amines by treatment with thiophosgene [14] or synthetic analogs thereof (Entry 5, Table 14.2). In an alternative two-step procedure, the amine is first treated with CS2 and a tertiary amine to yield an ammonium dithiocarbamate, which is subsequently desulfurized with TsCl or a chloroformate (Entry 6, Table 14.2 Experimental Procedure 14.1). Highly reactive acyl isothiocyanates have been prepared from support-bound acyl chlorides and tetra-butylammonium thiocyanate (Entry 7, Table 14.2). These acyl isothiocyanates react with amines to give the corresponding 7V-acylthiourcas, which can be used to prepare guanidines on insoluble supports (Entry 6, Table 14.3). 

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