Halogens sodium hypochlorite

By treatment of an amide with sodium hypobromite or sodium hypochlorite solution (or with the halogen and alkali), the amine of one less carbon atom is produced, the net result being the elimination of the carbonyl group. An example is ... 

Hypohalite ions, XO, are formed when a halogen is added to the aqueous solution of a base. Sodium hypochlorite, NaClO, is produced from the electrolysis of brine when the electrolyte is rapidly stirred, and the chlorine gas produced at the... 

Treatment with sodium hypochlorite or hypobromite converts primary amines into N-halo- or N,N-dihaloamines. Secondary amines can be converted to N-halo secondary amines. Similar reactions can be carried out on unsubstituted and N-substituted amides and on sulfonamides. With unsubstituted amides the N-halo-gen product is seldom isolated but usually rearranges (see 18-13) however, N-halo-N-alkyl amides and N-halo imides are quite stable. The important reagent NBS is made in this manner. N-Halogenation has also been accomplished with other reagents, (e.g., sodium bromite NaBr02) benzyltrimethylammonium tribromide (PhCH2NMe3 Br3"), and NCS. The mechanisms of these reactions involve attack by a positive halogen and are probably similar to those of 12-47 and 12-49.N-Fluorination can be accomplished by direct treatment of amines °° or... 

Halogenation of 2-methyl-l,3,4-thiadiazole 9 can be achieved under free radical conditions. Trichloro- and tribromomcthyl-l, 3,4-thiadiazolcs have been obtained by this method <1980LA1216>. Rapid and selective free radical monochlorination of the 2-mercapto-5-methyl-l,3,4-thiadiazole 9 was achieved using sodium hypochlorite under microwave conditions (Equation 27) <1998JCM586>. 

A convenient procedure for the oxidation of primary and secondary alcohols was reported by Anelli and co-workers (8,9). The oxidation was carried out in CH2CI2 with an aqueous buffer at pH 8.5-9.5 utilizing 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO, 1) as the catalyst and KBr as a co-catalyst. The terminal oxidant in this system was NaOCl. The major disadvantage of using sodium hypochlorite or any other hypohalite as a stoichiometric oxidant is that for each mole of alcohol oxidized during the reaction one mole of halogenated salt is formed. Furthermore,... 

Among the oxidative procedures for preparing azo compounds are oxidation of aromatic amines with activated manganese dioxide oxidation of fluorinated aromatic amines with sodium hypochlorite oxidation of aromatic amines with peracids in the presence of cupric ions oxidation of hindered aliphatic amines with iodine pentafluoride oxidation of both aromatic and aliphatic hydrazine derivatives with a variety of reagents such as hydrogen peroxide, halogens or hypochlorites, mercuric oxide, A-bromosuccinimide, nitric acid, and oxides of nitrogen. 

The traditional method of oxidizing hydrazine derivatives makes use of halogens or hypohalites as oxidizing agents. The techniques range from the preparation of l,l -azobis(l-cyclohexanenitrile) by the addition of bromine to an alcoholic hydrochloric acid solution of the corresponding hydrazine [89], through the use of bromine water [90, 91] to oxidations with sodium hypo-bromite [64] or sodium hypochlorite [92]. 

Still another method for the conversion of halides to acid derivatives makes use of Na2Fe(CO)4. As described in 0-102, primary and secondary alkyl halides and tosylates react with this reagent to give the ion RFe(CO)4 (141) or, if CO is present, the ion RCOFe(CO)4 (142). Treatment of 141 or 142 with oxygen or sodium hypochlorite gives, after hydrolysis, a carboxylic acid.1613 Alternatively, 141 or 142 reacts with a halogen (for example, I2) in the... 

Chloroindole has been prepared from indole and sulfuryl chloride (66JOC2627) and 3-bromo- and 3-iodo-indole have been obtained by direct halogenation in DMF (82S1096). 2-Methylindole reacts with sodium hypochlorite in carbon tetrachloride to give a 2 1 mixture of 1,3- and 3,3- dichloro derivatives (81JOC2054). 3-Substituted indoles are halogenated to yield 3-haloindolenium ions which react in a variety of ways, as illustrated by the reaction of 3-methylindole with NBS in aqueous acetic acid (Scheme 12). 

N-Halogenation as the preliminary step of indirect grafting on polyamide backbone is another interesting method which was studied with good results by Bamford and co-workers (150). The N-chlorination was undertaken by immersion for several minutes at room temperature in an aqueous solution of sodium hypochlorite to which acetic acid was added until reaching pH 4—4.5, followed by washing with distilled water and drying in vacuum at 40° C. N-Bromination... 

Exercise 17-12 Trichloromethane (chloroform) at one time was synthesized commercially by the action of sodium hypochlorite on ethanol. Formulate the reactions that may reasonably be involved. What other types of alcohols may be expected to give haloforms with halogens and base ... 

The most recent enhancement of bromine biocide chemistry is the development of a stabilized single liquid bromine, under the brand Stabrex , from Nalco (now owned by Degremont/Suez Lyonnaise Des Eaux). The product is most likely a sodium hypochlorite/sodium bromide mix, stabilized with sulfamic acid. It contains 14% available halogen as Br (6% as Cl), and is stable for several months. Stabrex probably has some benefits over other bromine chemistries, but is also a premium priced product. 

Sodium bromate, 0257 Sodium chlorite, 4032 Thallium bromate, 0260 CHLORITE SALTS METAL HALOGENATES METAL HYPOCHLORITES METAL PERCHLORATES... 

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