IV-Bromosuccinimide

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. 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. 

Benzodioxocin (14) can also be prepared starting from the dihydro derivative 17.14 Whereas an attempted bromination-didehydrobromination procedure was not successful, the required dehydrogenation was achieved by bromination with A -bromosuccinimide and treatment with triethylamine, by double bromination with iV-bromosuccinimide and debromination with zinc, or by pyrolysis of a diacetate derived from 17 by bishydroxylation and acetylation.14... 

The most common preparative procedures involve use of the halogen, usually bromine, in acetic acid. Other suitable halogenating agents include IV-bromosuccinimide, tetrabromocyclohexadienone, and sulfuryl chloride. 

Treatment of compound C with IV-bromosuccinimide in acetic acid containing sodium acetate gives a product C13H19Br03. Propose a structure, including stereochemistry, and explain the basis for your proposal. 

The silver-salt method was used by Porter and Gilmore in one of the first syntheses of 2,3-dioxabicyclo[2.2.1]heptane 936). Reaction of bicyclopentane with 98% H202 and IV-bromosuccinimide (NBS) in ether at —41 °C afforded mainly a 1 1 mixture... 

The steric course of electrophilic additions of BrN3, IN3, and iV-bromosuccinimide (NBS) to the tetrahydropyridazine ring of benzo[g]pyridazino[l,2- ]phthalazine-6,13-dione system, for example, 130, has been studied and the results are shown in Scheme 12 <1997CJC348>. 

The CDE rings of camptothecin were synthesized via an intramolecular Knoevenagel condensation of 124 (Equation 30) <2004TL7247>. The tricyclic dihydropyridone 125 was aromatized to the pyridone with NBS/ KHMDS (NBS - iV-bromosuccinimide, KHMDS - potassium hexamethyldisilazane). 

Diazaquinones 68, 83a, and 90 have been shown to provide adducts with various isoprenoids, as exemplified by the /3-myrcene adduct 140 (87H193). The side-chain double bonds of these adducts can be functionalized by epoxidation with 3-chloroperoxybenzoic acid or via bromination with IV-bromosuccinimide to provide the corresponding derivatives 141 and 142, respectively (Scheme 34). 

Several examples of the synthesis of furoxans by dimerisation of nitryl oxides are shown below. The treatment of oximes 302 with iV-bromosuccinimide (NBS) and then with triethylamine leads to the formation of nitrile oxides 303, as shown by the presence of a strong IR absorption band at around 2300 cm 1 typical of the CNO group stretching. Slow dimerization of nitrile oxides 303 took place at room temperature leading to the furoxans 304 in good yields (Scheme 75 and Table 4) <2002S1701>. 

Oxidation of Ar,A -bis(benzothiazol-2-yl)thiourea 292 with iV-bromosuccinimide (NBS) affords the crystalline tetra-azathiapentalene 15 (Equation 40) <2004EJ04203>. 

IV-bromosuccinimide (NBS) led to monobromide 103 (Equation 12), whereas with 104, both methyl groups were transformed, giving the dibromide 105 (Equation 13) <2004JHG549>. 

These compounds can be prepared by the action of bromine on a trialkyl phosphite,2 but a more satisfactory method recently worked out by Goldwhite and Saunders3 consists in treating the dialkyl hydrogen phosphite with iV-bromosuccinimide. In this way dimethyl, diethyl w-propyl and isopropyl phosphoro-bromidates have been obtained as pure liquids by distillation at very low temperature. When kept at ordinary temperatures, they gradually decompose with the evolution of the corresponding alkyl bromide. 

IV-Bromosuccinimide, Dibenzoyl peroxide, 4-Toluic acid, 1425 Chlorine, 4047... 

At variance with homohypostrophene, the related hypostrophene (42) reacts with bromine or with iV-bromosuccinimide in wet dimethyl sulfoxide to give products arising from an extensive structural rearrangement, i.e. the ewr/o -d i cy c I o pen tad i cn e derivatives... 

The action of bromine on potassium tris-malonatocobalt(iii) leads only to decomposition however, with iV-bromosuccinimide in CC, K3[Co(bromo-malonatelj] is formed.The structure of [Co(amidoxalato)2(H20)2]2H20 shows it to have a rra s-octahedral structure, the amido-oxalate ligands chelating via one carboxylate oxygen and the amidic oxygen. 

Use of iV-bromosuccinimide in methanol in the presence of sodium methoxide or DBU as a base traps the isocyanate intermediate as a carbamate. i. 180 181... 

Selective bromination of monobromo-substituted dithienyl sulfides with iV-bromosuccinimide afforded two more dithienothiophene isomers. From the reaction of 3-thienylIithium with disulfide 182 at —70°, 4-bromo-3,3 -dithienyl sulfide (185) was isolated. Bromination with 7 T-bromosuccinimide provided 2,4 -dibromo-3,3 -dithienyl sulfide (186) dilithiation of the latter followed by oxidative ring closure gave dithienothiophene 9 in 13% overall yield [Eq. (54)]. 

IR spectroscopy has shown that thienothiophenes 1 and 2 are brominated with iV-bromosuccinimide to furnish dibromo along with monobromo derivatives. An unpurified bromination product of thienothiophene 1 contained 8% of the initial thienothiophene 1,83% of 2-bromothieno[2,3-fe]thiophene, and 9% of 2,5-dibromothieno[2,3-fc]-thiophene 15% of the initial thienothiophene 2, 70% of 2-bromothieno-[3,2-6]thiophene and 15% of 2,5-dibromothieno[3,2-6]thiophene were detected on bromination of thienothiophene 2. ... 

Bromination by two equivalents of IV-bromosuccinimide in glacial acetic acid gave good yields (65% and 88%) of 2,5-dibromo derivatives of thienothiophenes 1 and 2, and 2,3,5-tribromo derivatives were obtained using ree equivalents of bromine in carbon disulfide (75% and 81% yields). ... 

Benzofuranyl)butanoic acid readily forms the acid chloride, and this undergoes intramolecular Friedel-Crafts acylation on treatment with tin(IV) chloride in carbon disulfide at room temperature, providing 1,2,3,4-tetra-hydro-l-dibenzofuranone (54%). " This intermediate has been converted to dibenzofuran by lithium aluminum hydride reduction and subsequent dehydrogenation, to 1-methyldibenzofuran by Grignard reaction and dehydrogenation, and to 1-dibenzofuranol by reaction with iV-bromosuccinimide and subsequent dehydrobromination with pyridine. 

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