Hydroxy cyanogen bromide

The hydroxy group of furazan 263 reacted with cyanogen bromide in glyme in the presence of Li2C03 to give cyanate 264 in 70-85% yield (97MI8). Upon treatment with Mc4NN3 and subsequently with a basic solution of hydroxylamine-0-sulfonic acid, /V-aminotetrazole 265 was obtained in 35% yield (Scheme 171). 

The unstable sodium salt of 5-chloro-3-mercapto-l,2,4-thiadiazole (336)151 reacts also with cyanogen bromide forming 5-chloro-3-thio-cyanato-l,2,4-thiadiazole (337).202 The sparingly soluble neutral sodium salt of 5-hydroxy-3-thiocyanato-l,2,4-thiadiazole (339) is similarly obtained (336->338->339) its free acid, like other 5-hydroxy-l,2,4-thiadiazoles, is fairly strong, but unstable.202... 

Mono- and di-thiocyanato-1,2,4-thiadiazoles, obtained by the stepwise action of cyanogen bromide on barium 3,5-dimercapto-l,2,4-thiadiazole, and on 5-chloro- and 5-hydroxy-3-mercapto-1,2,4-thiadiazole, are somewhat labile. The structures of certain of their transformation products (e.g. mono- and di-sulfides), which may have one of several isomeric forms, are not fully elucidated. The reactivity of their cyano group, resembling that in cyanogen halides, is noteworthy it is easily removed by the action of alkalis, the parent thiol being regenerated.202... 

Method A. A high molecular weight polysaccharide was activated by reaction with cyanogen bromide at basic pH, in a similar fashion Sepharose is activated for affinity chromatography. The reaction takes place at all possible hydroxy groups to produce 0-CN randomly... 

The precursor was obtained by demethylation of the parent N-Me compound by the use of well-established reagent, cyanogen bromide. Others are butorphanol (the only compound derived from a non-natural source) a 14-hydroxy-N-cyclobutylmethyl compound in which the oxide... 

Norlatifoline had been previously synthesized 97) from conessine via 3 -hydroxyconan-5-ene by cyanogen bromide degradation or, alternatively, from 3a,5a-cycloconan-6-one by von Braun degradation and re-formation of the 3 3-hydroxy-5,6-unsaturated steroid system. 

Hydroxycodeinone was first represented as an a-hydroxy-ketone, but such a formulation was rejected by Gulland and Robinson [9] on account of the stability of the base towards alkaline silver and cupric solutions, and, moreover, the base does not behave as an allylamine in its reaction with cyanogen bromide [4, 13-16]. A /3-hydroxy-ketone structure was never seriously considered and is in any case at variance with the observed difficulty of dehydrating 14-hydroxycodeinone and its derivatives, but a y-hydroxy-ketone formulation is compatible with all the experimental facts. 14 Hydroxycodeinone does not show the properties of a methylene-ketone, but its dihydro-compound does, facts best explained by postulating the presence of the system —GO—0—C—C—OH in the former [9]. 

Pregnane Series. Steroid allyl and propargyl enol ethers tindergo the Claisen rearrangement. - Surprisingly, cyanogen bromide reacts with 18-hydroxy-20-dimethylamino steroids to form the corresponding 18,20-epoxy deri-vatives. Additional work has been reported on the synthesis of l8-methyl steroids. ... 

PEPTIDES Azidotris(dimethylamino)phosphonium hexafluorophosphate. Benzotriazole-N-hydroxytris(dimethyIamino)phophoniuin hexafluorophosphate. Cyanogen bromide. Dicyclohexylcarbodiimide. Diethyl phophorocyanidate. 2-Ethyl-7-hydroxybenzis-oxazolium tetrafluoroborate. 1-Hydroxybenzotriazole. N-Hydroxy-S-norbornene-cndo-... 

The starting material for the synthesis is oxymorphone, the hydroxy-groups of which are first esterified with acetic anhydride, before the N-methylgroup is cleaved off with cyanogen bromide. After acid hydrolysis of the esters, the keto-group is reduced wth sodium borohydride, and the nitrogen finally alkylated with cyclobutylmethyl bromide. [108]... 

When the enzyme is incubated with /J-chloro-L-alanine, the rate of the catalytic reaction declines rapidly as the enzyme becomes irreversibly inhibited. Such inactivation is associated with the binding of close to 1 mole of the 3-carbon chain of the substrate analog per mole of active site. The enzyme, after inactivation by treatment with /8-chloro-L-[ C] alanine, was treated with cyanogen bromide and a C-labeled peptide was then isolated. Treatment of the labeled peptide with mild alkali leads to release of /8-hydroxy-[ CJpyruvate, suggesting an ester linkage. Ammonolysis of the labeled peptide leads to release of the label, and amino acid analyses of enzymic hydrolyzates of the peptide before and after ammonolysis show formation of an equivalent amount of glutamine [Eq. (3)]. The findings indicate that the labeled derivative... 

Immobilization Method. For the immobUization of proteins, a selection of amino, hydroxy, mercapto, and carboxy group spedfic methods should be used. For example, cyanogen bromide, tresyl, N-hydroxysucdriiriiide, epoxy, divinyl-sulfone, cyanuric chloride, and carbodiimide. The most promising method can then be further optimized. 

Hydroxy-3-phenylthiopropylamine stirred ca. 20 hrs. with cyanogen bromide and Na-acetate as acid acceptor in methanol 2-amino-5-phenylthiomethyl-2-oxazoline. Y 88%. F. e. s. E. R. Freiter, A. H. Abdallah, and S. J. Strydcer, J. Med. Chem. 16, 510 (1973) with CICN, without acid acceptor, stereospecific ring closure with retention or inversion of configuration, interconversion of stereo-isomeric 2-aminoalcohols, s. H. Wollweber and R. Hiltmann, Arch. Pharm. 306, 284 (1973). 

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