Bromosuccinimide

A -Bromosuccinimide (prepared by the action of bromine on succinimide at o in the presence of sodium hydroxide) is a valuable specific reagent for brominating olefines in the a-methylene position to the double bond without simultaneously adding bromine to this bond. For example, if A -bromosuccini-mide is represented by (C4H40t)NBr —... 

The substitution is best carried out by boiling A -bromosuccinimide with the olefine in carbon tetrachloride. Succinimide crystallises out from the carbon tetrachloride on cooling w hereas the brominated product remains dissolved in the carbon tetrachloride. 

Required Ethyl crotonate, 22-8 g. V-bromosuccinimide, 35 6 g. carbon tetrachloride, 40 ml. 

Dissolve 22-8 g. of ethyl crotonate in 40 ml. of dry carbon tetrachloride and add 35 6 g. of. V-bromosuccinimide. Heat the mixture under reflux for three hours. Cool to o and filter off the succinimide which is insoluble in cold carbon tetrachloride. Now shake the filtrate with water in a separating funnel, separate and dry the carbon tetrachloride layer with sodium sulphate. Filter through a fluted filter-paper into a Claisen flask and distil... 

The direct introduction of a halogen atom (usually bromine) by means of V-haloamine (generally iV-bromosuccinimide) in the allyl position is known as the Wohl-Ziegler reaction ... 

METHYL y-BROMOCROTONATE JV-Bromosuccinimide. Dissolve, with the aid of rapid mechanical stirring, 80 g. of pure succinimide (Section V,14) in a mixture of 150 g. of finely crushed ice and a solution of 32 g. of sodium hydroxide in 200 ml. of water contained in a litre beaker and cooled externally by ice. Immediately the imide has dissolved, continue the vigorous stirring and introduce 42 -5 ml. of bromine in one lot from a separatory funnel supported over the beaker it is essential that the bromine be instantly suspended in the solution. After stirring vigorously for 2 minutes, filter at the pump and... 

Methyl y-bromocrotonate. Mix 36 g. of iV-bromosuccinimide, 40 g. of methyl crotonate and 60 ml. of dry, redistilled carbon tetrachloride in a 500 ml. round bottomed flask. Reflux ou a water bath for 12 hours by this time all the sohd should have risen to the surface of the liquid. Filter off the succinimide at the pump and wash it with a little dry carbon tetrachloride. Remove the solvent on a water bath and distil the residue under reduced pressure, preferably from a Widmer flask (compare Figs. II, 24, 4-5). Collect the methyl y-bromocrotonate at 77-78°/8 mm. the yield is 31 g. 

The addition of N-bromosuccinimide (1.1equiv) to a dichlo-romethane solution containing the alkene (1 equiv) and cyana-mide (4 equiv). The solution was maintained at room temperature (3 days) and then washed with water, dried, and concentrated in vacuo. Treatment of the bromocyanamide [intermediate] with 1% palladium on charcoal in methanol (1h) led to reduction of the for-madine. Addition of base to the reaction mixture (50% aqueous KOH, reflux 6h) followed by extraction with ether gave monoamine. (Yield is 48-64% final amine from alkenes analogous to safrole)... 

Benzodioxole - 122g Bromosuccinimide -188g Chloroform - 500ml... 

Bromosuccinimide - easily purchased but I could only find one grade, ft s a very fluffy light orangy crystalline powder - use gloves and a mask, because bromine is VERY nasty. 

Bromination has been described using brominating agents such as N-bromosuccinimide in carbon tetrachloride (418. 420) bromine in either chloroform, acetic acid, or hydrochloric acid (414. 418, 421-423) bromine in sulfuric acid (415-417) and enzymatic catalysis (424, 425). 

The bromination with N-bromOsuccinimide in CCU can be accomplished yielding to 2-brOmothiazole (12.5% yield) (27). 

Halogenation (Section 11 12) Free radical halo genation of alkylbenzenes is highly selective for substitution at the benzylic position In the exam pie shown elemental bromine was used Alterna Lively N bromosuccinimide is a convenient re agent for benzylic bromination... 

A certain compound A when treated with N bromosuccinimide and benzoyl peroxide under photochemical conditions in refluxing carbon tetrachloride gave 3 4 5 tnbromobenzyl bromide in excellent yield Deduce the structure of compound A... 

The content of ascorbic acid, in milligrams per 100 mL, in orange juice is determined by a redox titration using either 2,6-dichlorophenolindephenol or N-bromosuccinimide as the titrant. 

Strecker Degradation (Oxidative Deamination), Mild oxidizing agents such as aqueous sodium hypochlorite or aqueous A-bromosuccinimide, cause decarboxylation and concurrent deamination of amino acids to give aldehydes. 

Halogen-substituted succinimides are a class of products with important appHcations. /V-Bromosuccinimide [128-08-5] mp 176—177°C, is the most important product ia this group, and is prepared by addition of bromine to a cold aqueous solution of succinimide (110,111) or by reaction of succinimide with NaBr02 iu the presence of HBr (112). It is used as a bromination and oxidation agent ia the synthesis of cortisone and other hormones. By its use it is possible to obtain selective bromine substitution at methylene groups adjacent to double bonds without addition reactions to the double bond (113). 

V-Bromosuccinimide and A/,A7-dibromo-5,5-dimethyIhydantoin have also been used successhdly, which makes possible recycling of succinimide or the hydantoin and utilizes all the bromine atoms. A mixture of sodium bromide—sodium bromate in aqueous acid has also been used commercially. 

Side-Chain Derivatization. Reaction of thiophene with aqueous formaldehyde solution in concentrated hydrochloric acid gives 2-chloromethylthiophene [765-50-4]. This relatively unstable, lachrymatory material has been used as a commercial source of further derivatives such as 2-thiopheneacetonitrile [20893-30-5] and 2-thiopheneacetic acid [1918-77-0] (24). Similar derivatives can be obtained by peroxide, or light-catalyzed (25) halogenation of methylthiophenes, eg, Ai-bromosuccinimide/benzoylperoxide on 2-, and 3-methylthiophenes gives the corresponding bromomethylthiophenes. 

The iacreased chemical stabiUty of the 6-deoxytetracyclines allows chemical modification with retention of biological activity electrophilic substitutions have been carried out at C-7 and C-9 under strongly acidic conditions (46—53). Reactions of 6-deoxy-6-demethyltetracycline [808-26-4] (16), C21H22N2O7, with electrophiles, such as nitrate ion (49), bromomium ion (46,47) (from N-bromosuccinimide), or N-hydroxymethylphthalimide (53), yielded 7-substituted tetracyclines. In the case of the nitration reaction, both the 7- and 9-nitro isomers (17, X = NO2, Y = H) and (17, X = H, Y = NO2) were obtained. 

V-bromosuccinimide [128-08-5] C H BrNOj 180-183 2.098 brominating olefins, oxidizing alcohols to aldehydes and ketones, converting aldehydes to acid bromides... 

The first pubHshed information on the halogenation of butyl mbber was provided by B. F. Goodrich Co. (2). Brominating agents such as /V-bromosuccinimide were used the bromination occurred ia a bulk reaction. This technology was commercialized ia 1954, but withdrawn ia 1969 (3). Exxon Chemical researchers pursued the chlorination of butyl mbber ia hexane solution usiag elemental chlorine, and a continuous process was commercialized ia 1961 (4). Currentiy, both chlorination and bromination are carried out ia continuous-solution processes. 

Treatment of pyrrole, 1-methyl-, 1-benzyl- and 1-phenyl-pyrrole with one mole of A -bromosuccinimide in THF results in the regiospecific formation of 2-bromopyrroles. Chlorination with IV-chlorosuccinimide is less selective (8UOC2221). Bromination of pyrrole with bromine in acetic acid gives 2,3,4,5-tetrabromopyrrole and iodination with iodine in aqueous potassium iodide yields the corresponding tetraiodo compound. 

Treatment of a carborane derivative of thiirane with A-bromosuccinimide gives a j3-bromodisulfide (79MI50601). Chlorination of CM-2,3-di-f-butylthiirane by f-butyl hypochlorite proceeded differently to the reaction with chlorine itself (Scheme 41) (74JA3146). 

---