Reactions of various heterocycles 1–6 with N ‐bromosuccinimide in the presence or absence of water have been studied for side chain versus ring bromination to afford some new and important heterocyclic synthons. Interestingly, the N ‐bromosuccinimide reaction in the presence of perchloric acid, a...
N-Bromosuccinimide is prepared by addition of bromine to a cold aqueous solution of succinimide or by reaction of succinimide with NaBrO2 in the presence of HBr. 1.62mol (160g) succinimide is dissolved in a mixture of 1.60mol (64g) NaOH, 300g crushed ice and 400ml water. Cool the mixtur...
aRing contraction was effected by reaction with trifluoroacetic acid and N-bromosuccinimide followed by aqueous sodium bicarbonate and silver tetrafluoroborate to give vinflunine in 88% yield. 圆环收缩由含水小苏打和银tetrafluoroborate跟随的反应与trifluoroacetic酸和N-bromosuccinimide在88%出产量影响给vinflunine。
To do so, sodium hydroxide and bromine are added to an ice-water solution of succinimide. The NBS product precipitates and can be collected by filtration. Crude NBS gives better yield in the Wohl-Ziegler reaction. In other cases, impure NBS (slightly yellow in color) may give unreliable ...
The reaction of 2-methylnorborn-2-ene with N-bromosuccinimide produced exo -3-bromo-2-methylenenorbornane and 2-methyl-3-bromonortricyclene in a 3:1 ratio. No 2-bromomethyl-norborn-2-ene was found. Most of the unreacted olefin was found to be isomerized to 2-methylenenorbornane. The...
Oxidizing agentsin an acidic environment irreversibly convert many colors into colorless substances. The spectrophotometric methods described rely on the reaction between RTG and an excess amount of NBS, followed by the measurement of NBS by its interaction with a set quantity ofAM, MB, and IC dye...
Following the reaction of DHP and NBS in acidic media, the excess NBS was evaluated for the first time by its interaction with P-aminophenol (PAP), which produced a violet-colored product that was detected at 556 nm. OBJECTIVE. The analytical method was performed and validated since different...
Two main mechanisms that differ in the reaction sequence of substrate were explored: styrene with NBS then followed by 2-aminopyridine (M1) or simultaneously with NBS and 2-aminopyridine (M2), and water-assisted M2 is the more favored one. We found that the adding sequence of 2-aminopyridine...
5a is formed in a result of transanular double bond participation.The reaction of 1 with NBS and methanol similarly produces 2, 3 , trans -6-bromo-5-methoxy-( Z )-cyclooctene ( 4b ), endo -6-bromo-2-methoxy- cis -bicyclo-[3.3.0]octane ( 5b ), and 6 ....
aromatic amides in good yields via treatment with N-bromosuccinimide in the presence of a catalytic amount of 2,2′-azobis(isobutyronitrile) in a mixture of ethyl acetate and water, acetonitrile and water, or chloroform and water, followed by reaction with molecular iodine and aq NH3 in one ...