Carbonyl isothiocyanates

Thioxo-1,2,4-dithiazolidines can be obtained from thioxo-l,2,4-thiadiazolidines by Dimroth rearrangement (Scheme 47) or reversibly by addition and elimination of acetone (Scheme 22). 1,2,4-Dithiazole type products are also obtained from thiocarbonyl isothiocyanates (154) by reaction with CI2 <84CHEC-I(6)897>, PhMgBr, Sj, or CS2. Other routes include reactions of carbonyl isothiocyanates and thiocarbonyl isocyanates with P4S10 or Sg <84Chec-I(6)897> and sulfonyl isocyanates with dialkyl thioketenes. Phenylisothiocyanate heated with N,C-disubstituted oxaziridines affords 3,5-diimino-l,2,4-dithiazolidines (226, 227). Other miscellaneous syntheses of 1,2,4-dithiazoline derivatives include cyclization of A7-thioacyl hexafluoroacetonimine to 5,5-bis(trifluoromethyl)-... 

HETEROCYCLES Copper phcnylace-tylide. Dichlorobis(benzonitrile)palladium. N-Dichloromethylene-N,N-dimcthylammo-nium chloride. Diiminosuccinonitrile. Dimethyl acetylenedicarboxylate. Dipotassium cyanodithioimidocarbonate. Ethoxy-carbonyl isothiocyanate. Ethyldiisopropyl-amine. Ethylene oxide. Hydrogen fluoride. Isocyanomethane-phosphoric acid diethyl ester. Lead tetraacetate. Lithium aluminium hydride. Methylhydrazine. Phosphoryl chloride. Polyphosphate ester. Polyphosphoric acid. Potassium amide. Potassium hydroxide. Tolythiomethyl isocyanide. Tosylmethyl isocyanide, Trichlo-romethylisocyanide dichloride. Trimethyl-silyldiazomethane. 

J-HALOVINYL KETONES Triphenylphosphine-Carbon tetrachloride. HETEROCYCLES Carbon suboxide. Diethyl isocyanomethylphosphonate. Ethoxy-carbonyl isothiocyanate. Propargyltriphenylphosphonium bromide. Selenium. HOMOALLYLIC ALCOHOLS 7r-2-Methylallylnickel bromide. 2-Methyl-2-thia-zoline. 

Thioacylation can be effected by the reaction of indoles such as compound (37) with ethoxy-carbonyl isothiocyanate to give the 3-substituted ethoxycarbonyl thioamide (38) (Equation (7)) <93TL3797>. 

S. Kulkami, 2000, Process for manufacturing N-alkoxy (or aryloxy)-carbonyl isothiocyanate derivatives using N,N-dialkylarylamine as cata-... 

Process for manufacture of N-alkoxy (or aryloxy)carbonyl isothiocyanate derivatives in the presence of N,N-dialkylarylamine catalyst and aqueous solvent, US 6,184,412 (Prio 10. 06. 1999), Bayer Corporation, Pittsburgh, PA, USA. 

Stable ionic 1 1 adducts 16 are also obtained when the reaction is conducted in toluene using carbonyl isothiocyanates. Further reaction of the dipoles with phenyl isocyanate affords tetraazaspiro[4,4]nonanes 17. ... 

In contrast, [2+2+2] cycloadducts 45 are obtained from from two equivalents of benzyli-dene methylamine and carbonyl isothiocyanates (R = COOEt, COSMe and CONPha) . 

The dimerization of carbonyl-, thiocarbonyl-, imidoyl- and thiocarbamoyl isothiocyanates proceeds in a [4-1-2] cycloaddition reaction (see Section 3.3.2.2). Carbonyl isothiocyanates also readily undergo [4-1-2] cycloaddition reactions with aliphatic and aromatic azomethines, the former being considerably more reactive. For example, phenylcar-bonyl isothiocyanate reacts with benzylidenemethylamine 184 to give a [4-1-2] cycloadduct 185... 

NN-disubstituted hydrazones." Heterocyclic compounds containing the l,2,4-triazoline-3-thione structure were formed in reactions between ethoxy-carbonyl isothiocyanate and hydrochlorides of amidrazones, phenyl isothiocyanate and anhydro-l-phenylimino-2,4,5-triphenyl-l,2,3-triazoline hydroxide, phenylhydrazones and thiocyanic acid, aroylhydrazines and... 

The interaction of 2-aminothiazole and ethoxy carbonyl isothiocyanate in ethyl acetate gives no less than four products, separable by chromatography. The N-ethoxycarbonyl-N -(2-thiazolyl)thioureas (149), which predominate amongst them (ca. 40—50%), appear not to undergo further cyclization spontaneously to the bicyclic products (150) except in one case (when R = Ph), but this ring closure does occur at 180 C. In each case, thiazolo[3,2-a]-sym-triazine-4-thione-2-one (148) was isolated in 20—40% yield, while (151) and (152) arose as minor products. ... 

Hydroxy-THISs add regioselectively to the C=N bonds of isocyanates or isothiocyanates. The initially formed cycloadducts eliminate carbonyl sulfide with formation of 4-hydroxy- or 4-mercaptoimidazolium hydroxide inner salts (21) (Scheme 21). 4-Hydroxyimidazolium hydroxide... 

Finally, formation of seven-membered rings by vinylaziridines possessing carbonyl or thiocarbonyl groups are shown in Scheme 2.46. Thermolysis of 182 in toluene at reflux yielded 4,7-dihydro-l,3-oxazepine 183 [71]. Similarly, treatment of N-unsubstituted vinylaziridine 184 with phenyl isothiocyanate in ether at 0 °C gave seven-membered ring 185, via a l-thiocarboxanilide-2-vinylaziridine intermediate [72]. 

The formation of compounds 2-503 proceeds via the addition of a hydrazide 2-500 onto the central carbon of an isothiocyanate 2-499. Subsequent cyclization by attack of the hydrazide nitrogen in the formed 2-501 onto the nitrile moiety gives intermediate 2-502. A further attack of the newly formed amidine nitrogen onto the carbonyl group followed by extrusion of water affords the triazoloquinolines 2-503. 

Formate esters behave as typical carbonyl compounds in reactions with a number of ylides, eliminating phosphine oxide and forming vinyl ethers, e.g. (33).35 Stabilized phosphoranes are able to condense with the carbonyl group of cyclic thioanhydrides (34).38 Quinoline derivatives, e.g. (35), are obtained from the condensation of dicar-boalkoxy-ylides with isocyanates.37 Benzoyl isothiocyanates and keto-phosphoranes give quantitative yields of (36), which are unreactive in Wittig reactions but can be readily oxidized by selenous acid.38 The products obtained from reactions (Scheme 9) with the triazolinedione (37) depend upon the stability of the ylide used.39... 

The anodic oxidation of substituted allenes [76-79] and hetero-allenes [80-85] has been extensively studied by Becker and coworkers. Oxidation of secondary and tertiary alkyl isothiocyanates resulted in an ot-cleavage processes [77]. Primary alkyl isocyanates yielded amides and carbonyl compounds due to the nucleophilic involvement of either acetonitrile or water [80]. Primary alkyl isothiocyanates 48 afforded five-membered thiadiazolidine 49 and 50 and... 

The carbon in the isothiocyanate grouping is highly susceptible to nucleophilic attack by the peptide s free amino group. Overall addition to the C=N creates a thiourea derivative. Making the conditions strongly acidic then promotes nucleophilic attack by the sulfur of the thiourea on to the carbonyl of the first peptide bond, producing a five-membered thiazoline heterocycle. Proton loss occurs from the nitrogen, and this creates an intermediate that is equivalent to the addition product in simple acid-catalysed amide... 

Iminophosphoranes have also proved to be key intermediates because they react with carbonyl compounds, isocyanates, isothiocyanates, acid chlorides, carbon dioxide, and carbon disulfide to give a wide range of imines and heterocumulenes, which are intermediates to pteridines. The preparation of iminophosphoranes has been investigated... 

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