Silver cyanate

Silver cyanate should be freshly prepared. The commercial material has a pronounced gray color and is totally unsuitable for this reaction. Best results are obtained when the following preparation is carried out in the dark. To 100 g of silver nitrate in 3 liters of distilled water is added with stirring 49.5 g of potassium cyanate in 700 ml of distilled water. The white precipitate is filtered through a large Buchner funnel (Coors No. 5) and the filter cake is washed with 500 ml water, then with 300 ml methanol, and finally with... 

Silver cyanate, AgNCO, consists of infinite chains of alternating Ag+ and NCO- ions. Ag+ has c.n. 2 and only one of the terminal atoms of the cyanate group is part of the chain skeleton, being coordinated to 2 Ag+. Decide with the aid of Pauling s second rule which of the cyanate atoms (N or O) is the coordinated one. (Decompose the NCO- to N3-, C4+ and O2-). 

A novel route to synthesize l,3 -triazine-2,4(l//,3//)-diones through the desulfurization of thiocarboamides, such as 1,3-disubstituted 2-thioureas, trisubstituted thioureas and N-substituted thioamides by silver cyanate has been reported <00H(53)929>. Treatment of urazole 23 with one equivalent of sodium hydride under anhydrous conditions, followed by addition of dimethyl sulfate, leads to l,3,5-triazine-2,4-dione 24 in 80% yield . 

A We calculate the solubility of silver cyanate, s, as a molarity. We then use the solubility equation to (1) relate the concentrations of the ions and (2) write the K expression. 

Silver cyanate, 0300 Silver cyanide, 0299 Sodium cyanide, 0536... 

Silicon tetraisocyanate is prepared from silicon tetrachloride and silver cyanate or lead cyanate. ... 

A 1-1. three-necked round-bottomed flask fitted with a mechanical stirrer, a thermometer, and a calcium chloride drying tube is immersed in an ice-salt bath. To the flask are added 38 g. (0.25 mole) of silver cyanate (Note 1), 34.7 g. of 75% 1,2-... 

I. I he purity of the silver cyanate used seems to be critical, lies , results arc obtained using product prepared in the following manner. A solution of 100 g. (0.59 mole) of silver nitrate in... 

Silver fulminate was recognized by Gay-Lussac16 to have the same composition as silver cyanate, thus providing the first example of isomerism. Two polymorphs of silver fulminate are known and their structures have been determined.17 Silver fulminate is regarded as a poor detonator due to its dangerous sensitivity this may depend on the presence or absence of the second form.17... 

Wohler converted two inorganic compounds, ammonium chloride and silver cyanate, into urea, an organic compound. 

See Mercury(II) cyanate, Potassium cyanate, Silver cyanate See also FULMINATING METALS... 

Silver cyanate, 0299 Silver cyanide, 0298 Sodium cyanide, 0533... 

Sulfuric acid, concentrated and dilute Silver nitrate Copper sulfate-pyridine test Cyanates, OCN Vigorous effervescence, due largely to evolution of carbon dioxide, with concentrated acid producing a more dramatic effect Curdy white precipitate of silver cyanate Lilac-blue precipitate (interference by thiocyanates) reagent is prepared by adding 2 or 3 drops of pyridine to 0.25 M CuS04 solution... 

The oxazolidin-2-ones 53 (R = H=CCH=CH2 or COEt) are obtained in a one-pot reaction of amino alcohol carbamates 52 with sodium hydroxide, followed by allyl bromide or propi-onyl chloride (94TL9533). A modified procedure for the preparation of chiral oxazolidin-2-ones 56 from a-amino acids 54, which avoids the hazardous reduction of the acids with borane and the intermediacy of water-soluble amino alcohols, is treatment of the methyl ester of the amino acid with ethyl chloro-formate to give 55, followed by reduction with sodium borohydride and thermal ring-closure of the resulting carbamate f95SC561). The 2-prop-ynylcarbamates 57 (R = Ts, Ac, Bz, Ph or allyl) cyclize to the methyleneoxazolidinones 58 under the influence of silver cyanate or copper(I) chloride/triethylamine (94BCJ2838). 

Decitabine (1) was first synthesized in 1964 by a multistep procedure described by Pliml and Sorm.17 In this preliminary communication, 5-aza-2 -deoxycytidine was prepared via cyclization of the peracylglycosyl isocyanate 5, which was prepared from silver cyanate and chloride 4.18,19 Addition of 2-methylisourea to 5 afforded the crystalline intermediate 6. Condensation of isobiuret derivative 6 with ethyl orthoformate resulted in the formation of crystalline triazine 7. Prolonged treatment with methanolic ammonia at room temperature afforded 1 -(2-deoxy-D-ribofiiranosyl)-5-azacytosine (8) as a mixture of a and (3 anomers. No yield was reported as the authors did not separate or distinguish between decitabine (1) and its a-anomer. 

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