Cyanation chloride

Peroxomonosulfuric acid oxidi2es cyanide to cyanate, chloride to chlorine, and sulfide to sulfate (60). It readily oxidi2es carboxyflc acids, alcohols, alkenes, ketones, aromatic aldehydes, phenols, and hydroquiaone (61). Peroxomonosulfuric acid hydroly2es rapidly at pH <2 to hydrogen peroxide and sulfuric acid. It is usually made and used ia the form of Caro s acid. 

Aryl, heteroaryl, and alkenyl cyanides are prepared by the reaction of halides[656-658] or triflates[659,660] with KCN or LiCN in DMF, HMPA, and THF. Addition of crown ethers[661] and alumina[662] promotes efficient aryl and alkenyl cyanation. lodobenzene is converted into benzonitrile (794) by the reaction of trimethylsiiyl cyanide in EtiN as a solvent. No reaction takes place with aryl bromides and chlorides[663]. The reaction was employed in an estradiol synthesis. The 3-hydroxy group in 796 was derived from the iodide 795 by converting it into a cyano group[664]. 

Alkylation. Ben2otrifluoride can also be alkylated, eg, chloromethyl methyl ether—chlorosulfonic acid forms 3-(trifluoromethyl)ben2yl chloride [705-29-3] (303,304), which can also be made from / -xylene by a chlorination—fluorination sequence (305). Exchange cyanation of this product in the presence of phase-transfer catalysts gives 3-(trifluoromethylphenyl)acetonitrile [2338-76-3] (304,305), a key intermediate to the herbicides flurtamone... 

Specialty Isocyanates. Acyl isocyanates, extensively used in synthetic appHcations, caimot be direcdy synthesized from amides and phosgene. Reactions of acid haUdes with cyanates have been suggested. However, the dominant commercial process utilizes the reaction of carboxamides with oxalyl chloride [79-37-8]. CycHc intermediates have been observed in these reactions which generally give a high yield of the desired products (86). 

Cyanide destmction by alkaline chlorination is a widely used process. With alkaline chlorination, cyanide is first converted to cyanate with hypochlorite [7681-52-9] at a pH greater than 10. A high pH is required to prevent the formation of cyanogen chloride [506-77-4] which is toxic and may evolve in gaseous form at a lower pH. With additional hypochlorite, cyanate is then oxidized to bicarbonate, nitrogen gas, and chloride. The pH for this second stage is 7—9.5 (6). 

The fumes of zinc chloride are highly toxic and can damage mucous membranes and cause pale gray cyanation. It can also ulcerate the skin of workers using it as a soldering flux or those handling wood impregnated with it (59). 

Benzyl chloride reacts with alkaH hydrogen sulfides, sulfides, and polysulfides to yield benzenethiol, dibenzyl sulfide, and dibenzyl polysulfide, respectively. With sodium cyanate it forms benzyl isocyanate (20). 

It is a very strong cyanating agent eg, it converts chloride ion to cyanogen chloride [506-77-4]. 

Dioxotetrahydro-l,3-oxazine derivatives (24) can be obtained by reacting jS-hydroxy acids with sodium cyanate to form a urethane derivative (23) followed by the action of thionyl chloride. ... 

Equation (1) shows the simple conversion of a quaternary ammonium anion exchange resin from the chloride form to the cyanate form. Equation (2) shows the reaction of the resin in the cyanate form with hydroxylamine hydrochloride whereby hydroxyurea is formed and the anion Cl is retained by the quaternary resin. 

Addition, chloroform, to olefins to form 1,1,3 tnchloroalkanes, 46, 106 chlorosulfonyl isocyanate to isobutylene to give 0-isovaleiolactam-N-sulfonyl chloride, 46, SI cyclohexyl amine to silicon tetraiso-cyanate, 46, 69... 

Capillary tube isotachophoresis using a potential gradient detector is another technique that has been applied to the analysis of alcohol sulfates, such as sodium and lithium alcohol sulfates [303]. The leading electrolyte solution is a mixture of methyl cyanate and aqueous histidine buffer containing calcium chloride. The terminating electrolyte solution is an aqueous solution of sodium octanoate. 

This is a problem that has been reported by several researchers in other cya-nation methods on heteroaromatic halides. (Hetero)aryl chlorides have also been tackled via in situ halogen exchange to (hetero)aryl bromides followed by sequential cyanation (Scheme 71). For this microwave-assisted process an equimolar amount of NiBr2 and a two-fold excess of NaCN were used. The only heteroaromatic chloride tested was 2-chloropyridine. Although the procedures described involve the use of significant amounts of nickel salts, a clear advantage is that the reactions can be performed in air. Moreover, the cyanat-ing reagents are easily removed since they are water soluble. 

Perhaps the most interesting finding of our synthetic studies was that the interfacial preparation of poly(iminocarbonates) is possible in spite of the pronounced hydrolytic instability of the cyanate moiety (see Illustrative Procedure 3). Hydrolysis of the chemically reactive monomer is usually a highly undesirable side reaction during interfacial polymerizations. During the preparation of nylons, for example, the hydrolysis of the acid chloride component to an inert carboxylic acid represents a wasteful loss. 

Salen ligands have also been used in the titanium-catalyzed trimethylsilyl-cyanation of benzaldehyde. The complexes were immobilized by substitution of a chloride with a surface silanol from the support. In the first study on this reaction [38], the most efficient ligand was the non-symmetrical salen Im (Fig. 11) (94% ee), whereas the selectivity obtained with the symmetrical ligand la was significantly lower (72% ee). In a recent paper, the immobilization of different titanium species, including monomeric and dimeric systems with... 

It is more convenient to start with the triflate ion [Rh(NH3)5(CF3S03)]2+ since triflate is a much better leaving group than chloride and is immediately replaced by liquid ammonia [87]. A third route involves acid hydrolysis of the cyanate complex [Rh(NH3)5(NCO)]2+, which proceeds quantitatively (probably via a carbamic acid complex). Vibrational studies on Rh(NH3) + assign stretching vibrations as i(Alg) at 514cm-1, i/2(Eg) at 483 cm-1 and i/j(T,u) at 472 cm-1 [88],... 

The acridanyl radical is also obtained from N-methylacridinium chloride 83 and potassium cyanide in air-saturated DMF, DMSO, or DMSO/water mixtures. It is a remarkably stable radical 137> when 83 is treated with excess cyanide and oxygen N-methylacridone and cyanate are produced with light emission ... 

Recently, the solvolyses of l-chloro-l,3,3-triarylallenes 10 (andof 1-butyl-3,3-diphenyl-allenyl chloride) were carried out in the presence of thiocyanate and o-ethyl dithiocar-bonate anions as nucleophiles and found to give the corresponding allenyl derivatives 11 and 12 in good yield (equation 3)18. However, when potassium cyanate was used as a nucleophile, the cyanate ion attacked at the /-position to give the propargyl amines 14 after decarboxylation of the unstable intermediate 13 (equation 4). 

Dipolar cycloaddition reactions, of nitrones to olefins, 46, 97 of 3-phenylsydnone, 46, 98 Dispiro[5.1.5.1]tetradecane-7,14-dione, photolysis to cyclohexylidene-cyclohexane, 47, 34 preparation from cyclohexanecarbonyl chloride and triethylamine, 47, 34 Displacement of bromine from 1-bromo-2-fluoroheptane to give 2-fluoro-heptyl acetate, 46, 37 N,N -Disubstituted formamidines from triethyl orthoformate and primary amines, 46, 41 N,N-Disubstituted thioureas from secondary amines and silicon tetra-isothiocyanate, 45, 69 N,N-Disubstituted ureas from secondary amines and silicon tetraiso-cyanate, 45, 69... 

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