Cyanogen alcohols

Cyanogen-hydroxyl Compotmds.— The cyanogen-alcohols are very similar to the amino-alcohols in their methods of formation. They may be formed from the chlor-hydrines by the action of potassium cyanide, as follows ... 

Sodium cyanide [143-33-9] NaCN, is a white cubic crystalline soHd commonly called white cyanide. It was first prepared in 1834 by heating Pmssian blue, a mixture of cyanogen compounds of iron, and sodium carbonate and extracting sodium cyanide from the cooled mixture using alcohol. Sodium cyanide remained a laboratory curiosity until 1887, when a process was patented for the extraction of gold and silver from ores by means of a dilute solution of cyanide (see Metallurgy, extractive). A mixture of sodium and potassium cyanides, produced by Edenmeyer s improvement of the Rodgers process, was marketed in 1890. 

Benzoylene urea has been prepared by passing cyanogen into a solution of anthranilic acid in alcohol and hydrolyzing the resulting 2-ethoxy-4-ketodihydroquinazoline, by fusing anthranilic acid with urea, and by the action of aqueous cyanic acid on anthranilic acid. The procedure described is adapted from that of Bogert and Scatchard with several modifications. 

Cyanogen chloride reacts with alcohols in the presence of an acid catalyst such as dry HCl or AICI3 to give carbamates ... 

The present method is shorter and less laborious than previously described methods, and it gives better yields of material. The method is one of considerable scope,6-8 having been used with fair to excellent success with many tertiary alcohols or the corresponding alkenes, with benzyl alcohol, and with some secondary alcohols. Nitriles (except cyanogen and phenylacetonitrile) generally have been found to react at satisfactory rates and in good yield. 

Hydrocarbons, alcohols, aldehydes, ketones, carboxylic adds, quinones, esters, lactones, phenolics, steroids, alkaloids, cyanogenic glycosides, sulfides, peptides, proteins Arachnida... 

The series of monomers NCO—CH2(CF2) CH2—OCN ( = 3, 4, 6, 8, 10) can be synthesized by the original method of Grigart and Piitter, in which a stoichiometric quantity of triethylamine is added to a cold solution of the alcohol and cyanogen halide (Reaction 1). 

Salicin is an (9-glycoside of a phenol, namely salicyl alcohol. Salicin is a natural antipyretic and analgesic found in willow bark, and is the template from which aspirin (acetylsalicylic acid, see Box 7.13) was developed. Prunasin from cherry laurel is an example of a cyanogenic glycoside, hydrolysis of which leads to release of toxic HCN (see Box 7.7). It is the (9-glucoside of the alcohol mandelonitrile, the trivial name for the cyanohydrin of benzaldehyde. It is the further hydrolysis of mandelonitrile that liberates HCN. 

Treatment of cyanoimidates, easily obtained from cyanogen and alcohols in the presence of triethylamine, gave with sulfur monochloride the corresponding 4-chloro-l,2,5-thiadiazoles 36 in good-to-moderate yields (1967JOC2823, 1998JMC379 Scheme 20). 

Allyl alcohols readily react with trichloroacetonitrile to give the corresponding trichloroacetimidates 145. Activation of the double bond with electrophilic reagents results in ring closure to yield oxazolines 146. The most commonly employed electrophiles include iodine, iodine monochloride, phenylselenyl chloride, and mercuric trifluoroacetate. Other nitriles including cyanogen bromide and N,N-dimethylcyanamide can also be used. Since oxazolines readily hydrolyze to amides, the net effect of this reaction sequence is to produce p-amino alcohols 147 from an allyl alcohol. This strategy has been employed in numerous total syntheses of natural products. Examples are listed in Table 8.18 (Fig. 8.7 Scheme 8.43). ° ... 

Cyanogen bromide reacts with amino alcohols to give 2-aminooxazolines that condense in the presence of benzaldehyde and p-toluenesulfonic acid with loss of ammonia to give aza-bis(oxazolines) 173. Aza-bis(oxazohnes) such as 173 are emerging as a new and important class of chiral ligands for asymmetric processes with the added advantage that they can be immobilized on solid supports (Scheme 8.50). 

Anhydrous hydrazine, Cyanogen bromide. Isopropyl alcohol, Sodiirm nitrite. Sodium bicarbonate. Copper nitrate trihydrate. Nitric acid. Diethyl ether... 

Nitric acid, N-Methyl gluconamide. Acetic anhydride. Sodium bicarbonate. Methanol Dimethylurea, Nitric acid, Sulfuric acid. Methylene chloride, Sodium carbonate Anhydrous hydrazine, Cyanogen bromide, Isopropyl alcohol, Sodium nitrite, Sodium bicarbonate, Copper nitrate trihydrate, Nitric acid, Diethyl ether, Dimethyl sulfate... 

These ethers are produced bj the substitutioa of hydroxyl in the alcohols by chlorine, bromine, iodine, fluorine, or cyanogen. 

C. Condensation of DAMN with Alcohol/Cyanogen Adducts... 

Acid-catalyzed condensation of DAMN with l,2-dialkoxy-l,2-diimino-ethanes, prepared by the reaction of alcohols with cyanogen (64CB1599), gives good yields of 2-alkoxy-3-amino-5,6-dicyanopyrazines, providing an equivalent of acid is used. This is illustrated in Scheme 29, with the methanol/ cyanogen adduct 71 giving the pyrazine 72. 

When R in the formimidate is —CH2CF3, 4,5-diamino-2,6-dicyano-pyrimidine forms. This occurs because —OCH2CF3 is a better leaving group than cyanide and is eliminated in the first step rather than cyanide. Cyanoformimidates are available from reaction of alcohols with cyanogen (75USP3883532). 

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