With hydrogen cyanate

HFA forms an adduct 102 with hydrogen cyanate that decomposes above 0°C. Storage over a long period produces oxadiazinedione 103 and loss of one molecule of HFA (143). 

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). 

Carbamyl and thiocarbamyl fluorides are obtained from hydrogen fluoride and cyanic acid or alkali metal cyanates or thiocyanates [/, 54] Nitnles give iraidofluoride salts with hydrogen fluoride [7] whereas hydrogen cyanide affords difluoromethylamine, which can be isolated as its hexafluoroarsinate salt [55) (equation II)... 

Acetylation of the hydroxymethyl imidazole 63 affords the corresponding ester (64), nitration (65) followed by hydrolysis gives intermediate 66, and reaction of this alcohol with potassium cyanate in hydrogen fluoride gives the carbamate ronidazole (67).16... 

Aqueous cyanide effluent containing a little methanol in a 2 m3 open tank was being treated to destroy cyanide by oxidation to cyanate with hydrogen peroxide in the presence of copper sulfate as catalyst. The tank was located in a booth with doors. Addition of copper sulfate (1 g/1) was followed by the peroxide solution (27 1 of 35 wt%), and after the addition was complete an explosion blew off the doors of the booth. This was attributed to formation of a methanol vapour-oxygen mixture above the liquid surface, followed by spontaneous ignition. It seems remotely possible that unstable methyl hydroperoxide may have been involved in the ignition process. 

A" 0-Butenolide, 46, 22 /-Butyl alcohol, in synthesis of phenyl /-butyl ether, 45, 89 reaction with sodium cyanate and trifluoroacetic acid, 48, 32 /-Butyl azidoacctatc, 46, 47 hydrogenation of, 45, 47 /-Butyl carbamate, 48,32 /-Butyl chloroacetate, reaction with sodium azide, 45, 47 /ra S-4-/-BuTYI,CYCLOHEXANOL, 47,16... 

In contrast an excess of KNH2, depending on the temperature, causes formation of hydrogen together with potassium cyanate or dipotassium urea ... 

Entries 1 and 2 in Table 8 are examples of an overall antarafacial 1,3-transposition of a hydroxy group by selenium compounds20,21. Treatment of the alcohols with 2-nitrophenyl seleno-cyanate in the presence of tributylphosphine gave the selenide with inversion of configuration. Oxidation with hydrogen peroxide led to the selenoxide, which rearranged suprafacially to the allylic alcohol. 

The reaction of benzaldehyde with hydrogen cyanide in the presence of 2 mol % of the catalyst in toluene at -20 °C for 8 h furnished the corresponding (i )-cyanohydrin in 97% yield and an enantioselectivity of 97%. The asymmetric cyanation of various aromatic and heteroaromatic aldehydes similarly proceeded to give the optically active cyanohydrins, although aromatic aldehydes with electron withdrawing groups such as NO2 and CN and aliphatic aldehydes... 

When primary amines (43 R6 = H) are used as the amine component, hydantoinimides (42e) and thiohy-dantoinimides (42f) result from hydrogen cyanate and thiocyanate as the acid component HX.53,54 The most important acid components are the carboxylic acids. With primary amines (43 R6 = H) they yield a-acylaminocarboxamides (42g),39,55-57 whereas with secondary amines (42 R1, R2 = organyl), the di-acylimines (42h) are the products, provided that acylatable nucleophiles are absent.55,58,59 The diacyl-imides (42h) are acylating reagents that transfer an R CO group, and so are their precursors, the a-adducts (41 X = R CCh).55... 

Two acids can be derived from 13.34 HOCN (cyanic acid or hydrogen cyanate) and HNCO (isocyanic acid, 13.35). It has been established that HOCN and HNCO are not in equilibrium with each other. Isocyanic acid (pA), = 3.66) is obtained by heating urea (equation 13.81) but rapidly trimerizes, although heating the trimer regenerates the... 

Reaction with cyanic esters 732 Carbon disulfide (2.28 g, 30 mmoles) in ether (5 ml) is dropped into a solution of the amine (30 mmoles) and triethylamine (3.03 g, 30 mmoles) in ether (20 ml) which is stirred and cooled in ice-water. The mixture is then left at room temperature for 1 h (or 24 h for aromatic amines), treated with phenyl cyanate (3.57 g, 30 mmoles), and diluted with ether (5 ml). The clear solution that results is extracted with dilute hydrochloric acid, with sodium hydrogen carbonate solution, and with water, concentrated, filtered from the precipitated phenyl thiocarbamate, and fractionated. Yields are about 60%. 

Recently Allenstein and Quis ( ) investigated the addition of hydrogen halides to thiocyanates. While with hydrogen chloride only labile adducts have been observed, hydrogen bromide adds to methyl- and phenylthio-cyanate to afford 2 1 adducts, for which structure XX has been assigned on the basis of infrared spectroscopy ( ). 

The reaction of aryl cyanates with hydrogen chloride or hydrogen bromide in an inert solvent produces the haloformimidinium halides XL ( ). 

The starting point for his synthesis was N,]SF-dimethylurea, the reaction of which with malonic acid gave N,N-dimethylbarbituric acid. With nitrous acid (sodium nitrite and a mineral acid) he produced dimethylvioluric acid, which gave dimethylpseudouric acid upon reduction and further reaction with potassium cyanate. Ring closure by heating with hydrochloric acid then led to 1,3-di-methyluric acid. [518] Its reaction with phosphorus pentachloride and reduction with hydrogen iodide then produced the supposed theophylline final... 

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