With potassium thiocyanate

A disubstitution reaction occurs in the condensation of 1,2-dichloroperfluoro-cycloalkenes with potassium thiocyanate [78] or potassium p-nitrothiophenoxide [79] (equation 71). 

The product is a mixture, however, the composition may be altered by the nucleophile used in the reaction For example, the reaction of perfluorobutyl iodide in the presence of sodium acetate or sodium bisulfite results mostly in perfluoro-2-butene and nonafluorobutane, whereas with potassium thiocyanate, perfluoro-1 butene is the dominant product, together with perfluoro-2-butene and a small amount of nonafluorobutane (equation 40)... 

Treatment of 3,4-dinitrofurazan with potassium thiocyanate in acetic acid at 10-20°C led to the corresponding thiocyanate 214 in 83% yield along with a small amount of 3-mercapto-4-nitrofurazan, whereas at 70-75°C the precursor was converted into a mixture of the disulfide 215 (38%) and tricycle 216 (27%). Thioether 217 was prepared in 78% yield by reaction of 3,4-dinitrofurazan and sodium sulfide (95MC25) (Scheme 145). 

These observations reported in the mid-30 s on the relative reactivities of the C-4 and C-6 tosylates toward a nucleophile such as sodium iodide, lay dormant until 1963, when it was found (60) that treatment of methyl 2,3-di-0-benzoyl-4,6-di-0-methylsulfonyl-a-D-glucopyranoside (14) with potassium thiocyanate at 130°C. for 48 hours afforded a 40% yield of the corresponding 4,6-dithiocyanato derivative 15. 

The reactivity at the C-4 position of hexose and hexoside sulfonates has been demonstrated in the gluco and galacto series and could undoubtedly be extended to other sugars as well. In another example (25), methyl 2,3-di-0-benzoyl-4-0-p-tolysulfonyl-a-D-glucopyranoside (18a) was treated with potassium thiocyanate in N,N-dimethylformamide at 140°C. for 9 hours to give the C-4 epimeric thiocyanato derivative 19 in 34% yield. The corresponding 4-p-bromobenzenesulfonate (18b) however, afforded a 55% yield of 19 in only 2% hours of reaction time. 

Ethylene carbonate, reaction with potassium thiocyanate, 42, 59 Ethylene sulfide, 42, S9 Ethyl formate, reaction with cyclo-hexylamine, 41, 14 Ethyl- -hexylamine, 43, 47 5-(2-Ethylhexyl)-l,2,3,4,5-pentachloro-cyclopentadiene, 43, 93 Ethylhydrazinium hydrogen oxalate,... 

Acylated glycosyl thiocyanates are made by treatment of acylated glycopyranosyl halides with potassium thiocyanate.30 Reaction at —40° with a Grignard reagent affords alkyl or aryl 1-thioglycosides.54... 

Au(C6F5)Cl2(CH2PPh2Me)] reacts with potassium thiocyanate to give trans-... 

A quite different use of a thiocyanate salt is the conversion of an epoxide (oxirane) to an episulfide (thiirane) this normally heterogeneous reaction is markedly accelerated by the use of silica gel coated with, or finely ground with, potassium thiocyanate, rather than with the thiocyanate salt alone.17... 

Condensations of amine hydrohalides with potassium thiocyanate (KSCN) provide both the primary thioureas and symmetrical 7V,7V -disubstituted thioureas. Selectivity in the product was achieved by changing the concentration of KSCN as shown in the diagram (Scheme 50).131... 

In a method described by Kiriyama and Kuroda [500], molybdenum is sorbed strongly on Amberlite CG 400 (Cl form) at pH 3 from seawater containing ascorbic acid, and is easily eluted with 6 M nitric acid. Molybdenum in the effluent can be determined spectrophotometrically with potassium thiocyanate and stannous chloride. The combined method allows selective and sensitive determination of traces of molybdenum in seawater. The precision of the method is 2% at a molybdenum level of 10 xg/l. To evaluate the feasibility of this method, Kiriyama and Kuroda [500] spiked a known amount of molybdenum and analysed it by this procedure. The recoveries for 4 to 8 xg molybdenum added to 500 or 1000 ml samples were between 90 and 100%. 

A series of 3-substituted 2-nitrosiminobenzothiazohnes (35a-e) as well as the disub-stituted analog 35f were prepared (Scheme 3.24) [198]. The reaction of an arylamine hydrochloride with potassium thiocyanate gave the corresponding unsymmetrical thiourea [199]. Oxidative cyclizations with bromine provide the iminobenzothia-zolines [191, 200], which on treatment with sodium nitrite in acetic acid afforded the nitrosiminobenzothiazoline (35a-f). The nitrosiminobenzoselenazoline (42) was similarly prepared. 

The reaction of compounds 161 with bromine followed by treatment with potassium thiocyanate affords 5-thiocyanato-6-arylimidazo[2,l-A][l,3,4]thiadiazoles 163 (Equation 4) <2000EJM853>. 

Activated haloarenes react with potassium thiocyanate under the influence of a quaternary ammonium salt to form the corresponding aryl thiocyanates [61]. Aliquat is preferred over tetra-n-butylammonium bromide for the reactions of fluoro- and iodoarenes but, in all cases, yields are extremely high. 

A single report of the addition of sodium azide to cyclohexene in the presence of iodine under phase-transfer catalytic conditions to produce 2-iodocyclohexanyl azide has the potential for extension to other alkenes [17], The analogous reaction of cyclohexene with potassium thiocyanate and iodine produces 2-iodocyclohexyl isothiocyanate (17%) and 2-iodocyclohexanyl thiocyanate (61%). Similar products are obtained with other alkenes [17],... 

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 4-oxo-2-thioxopyrimidines 472 (cis, X = CH2, CH2CH2 trans, CH = CH, CH2CH2), readily prepared from amino esters with potassium thiocyanate, gave the tricyclic 1,3-thiazinopyrimidinones 473 by addition of dimethyl acetylene dicarboxylate (DMAD) (89MRC959). In this reaction, the first step is probably a Michael addition of DMAD to the tautomeric 2-SH group, and thereafter cyclization of the ester on the ring NH occurs. 

The synthesis of 7-amino-3-[[(2,5-dihydro-6-hydroxy-2-methyl-l,2,4-triazin-5-on-3-yl)thio]methyl]-3-cefem-4-carboxylic acid (32.1.2.70) is done in parallel. In order to do this, methylhydrazine is reacted with potassium thiocyanate to give 1-amino-1-methylthiourea... 

Another of the suggested methods consists of the initial reaction of styrene oxide with ethyl-enimine to makeiV-(2-phenyl-2-hydroxyethyl)ethylenimine (38.1.29), which is reacted with potassium thiocyanate or with thionrea to give l-(2-phenyl-2-hydroxyethyl)-2-imino-l,3-thiazolidine (38.1.28). hi the aforementioned manner, the prodnct is treated first with thionyl chloride and then with acetic anhydride to make tetramizole [26-31]. 

Nonactin, isolated from actinomyces, is a macrotetrolide, (VI), which complexes alkali metal salts in the sequence Li < < Na+, Cs+< Rb+< K+. The crystal structures of its complex with potassium thiocyanate and of the uncomplexed molecule have been determined. 

The thermal condensation of a cyclic carbonate with potassium thiocyanate represents a practical method for the synthesis of the four-membered S-ring system (Eq. 10a). ... 

A variety of methods exist for the formation of 1,2-thiazines via the construction of an S-N bond by nucleophilic attack of nitrogen onto a sulfur-bearing leaving group. For example, the reaction of aryl bromide 189 with potassium thiocyanate in the presence of copper(l) iodide and triethylamine affords benzothiazine 190, although in low yield and as a mixture with indoline by-product 191 (Equation 28) <2000JOC8152>. 

Bis(bromomethyl)-l,3,5-cycloheptatriene 219 reacted with potassium thiocyanate in refluxing ethanol and afforded quantitatively the corresponding bisthiocyanate 220, which could be transformed readily to 3,6,9-trihydro-cyclohepta[i/ [l,2]dithiin 221 in 70% yield with NaBH EtOH/THF (cf. Scheme 62) <2006H(68)1031>. 

The aminothiazole ring of the novel opioid derivative 191 is produced on reaction of the corresponding amine with potassium thiocyanate and bromine in acetic acid (Equation 126) <2004JME1886>. 

An orange-coloured precipitate of m-dithiocyanato-diethyiene-diamino-chromic thiocyanate, [Cr en2(SCN)2](SCN), is produced on warming an aqueous solution of the salt with potassium thiocyanate, and a sparingly soluble chromithiocyanate, [Cr en2(H402)Br]3[Cr(SCN)6]. 2H20, is precipitated on mixing a freshly prepared aqueous solution of the bromide with potassium chromithiocyanate. It crystallises in violet-red transparent needles which are almost insoluble in water and decompose on exposure to light.2... 

The bromo-aquo-salts belong to the cis-series, as on treatment with potassium thiocyanate only m-dithiocyanato-chromic thiocyanate is obtained and no fraus-salt.3... 

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