IV-chlorosuccinimide

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. 

Cleavage of the oxathiane moiety can be carried out with iV-chlorosuccinimide/silver nitrate and leads to the a-hydroxy aldehyde 21 along with a diastereomeric mixture of sultines 20. The sultines can be reduced to the hydroxy thiol 22 which can be reconverted to the chiral auxiliary 16 in ail overall recovery of about 70%39. 

The reaction of alcohols with SnCl2 in the presence of IV-chlorosuccinimide affords alkoxytrichlorotin(IV) compounds or their disproportionation products, dialkoxydichlorotin(IV) and SnCLt332. 

If a deoxyribonucleoside 5 -monophosphate is first esterified with a bulky apolar group, and then used as the 5 -terminus for synthesis of an oligodeoxyribonucleotide, reaction products may conveniently be isolated by solvent-extraction techniques, up to about the tetranucleotide stage. 2-(4-Tritylphenyl)thioethanol (69) and 2-(4-tritylphenyl)sulphonylethanol (70) have been used for this purpose.119 For deblocking, (69) is first oxidized to (70) with iV-chlorosuccinimide and then removed with alkali. 

The Beckmann rearrangement of ketoximes with triphenylphosphine and iV-chloro-succinimide occurs at room temperature almost instantaneously and their corresponding secondary amides are obtained in high yields (equation 83). The triphenylphosphine 271 is activated by the iV-chlorosuccinimide 270 affording the salt 272, which is attacked by the iV-hydroxy group of the oxime 217 forming the intermediate 273. 

Bugge used PMR spectroscopy to confirm the structures of the products obtained on chlorination (iV-chlorosuccinimide), acetylation... 

Recently Bugge studied the reactivities of thienothiophenes 1 and 2 and thiophene by the competitive method, utilizing SnCl4-catalyzed acetylation with acetic anhydride, Vilsmeier formylation and chlorination with iV-chlorosuccinimide. Thienothiophenes 1 and 2 are always more reactive than thiophene. In acetylation the reactivities of 1 and 2 are similar, while in formylation and chlorination thienothiophene 2 is somewhat more reactive than isomer 1 (Table V). 

With one equivalent of IV-chlorosuccinimide (NCS) in acetic acid at 25°, thienothiophene 1 gives the initial thienothiophene 1 (11%), 2-chloro- (78%) and 2,5-dichlorothieno[2,3-6]thiophene (10%), while a 70% yield of 2,5-dichlorothieno[2,3-6]thi(q)hene is produced with two equivdents of NCS. Similar results were obtained from thienothiophene 2 with one and two equivalents of NCS. About 0.4% 3-chlorothieno[2,3-6]thiophene was detected by gas-liquid chromatography among the chlorination products of 1. The same amount of /9-isomer is found in thiophene chlorination products. In the case of thienothiophene 2, the corresponding /9-isomer was not observed in the reaction products. To identify 3-chloro-substituted thiophene and thienothiophenes 1 and 2 in reaction mixtures, these compounds were prepared independently from the corresponding 3-bromo derivatives by Uthiation followed by chlorination at —70°. 

The step 3 was reacted with IV-chlorosuccinimide and the heterocyclic intermediate isolated in 82% yield. 

IV-Chlorosuccinimide [128-09-6] M 133.5, m 149-150°. Rapidly crystd from benzene, or glacial acetic acid and washed well with water then dried in vacuo. [Phillips and Cohen JACS 108 2023 1986. 8-Chlorotheophylline [85-18-7] M 214.6, m 311°(dec). Crystd from water. 

Benzoxazines and 1,2-benzothiazines are rarely encountered except as carbonyl derivatives or as 5-oxides respectively. However, an interesting representation of the 2,1-benzothiazine system is provided by the zwitterion (9) which is formed by successive treatment of the 2-aminostyrene (8) with iV-chlorosuccinimide and potassium hydroxide (see Section 2.27.3.1.1. ii). On protonation it gives the salt (10). 

Even forcing conditions did not cause the anhydro-D-fructose derivative 53 to undergo photochlorination with iV-chlorosuccinimide, but, with sul-furyl chloride-azobis(isobutanonitrile) in refluxing carbon tetrachloride, it gave several products, one of the major being the crystalline a-chloro analog of the bromide 56 (14% isolated).50... 

The /rans-3 -benzylth io-3-ch Ioro- ( -1 actams 192, the appropriate (3-lactam car-bocation equivalents, were prepared by stereospecific chlorination of their corresponding frans-3-benzylthio-(3-lactams 191 using IV-chlorosuccinimide and catalytical amount of AIBN [125]. These (3-lactam carbocation equivalents 192 on treatment with propargyl alcohol or allyl alcohol in the presence of ZnCVSiCL were further transformed to suitable substrates, such as, m-3-benzylthio-3-(prop-2-ynyloxy/enyloxy)-(3-lactams 193 and 195 respectively [126]. 

Hydroxyhexanal undergoes a Claisen reaction with isopropenyl acetate in the presence of iV-chlorosuccinimide and tin(ll) chloride as catalyst to afford 2-acetonyloxepane. In the case of 6-hydroxy-2-pentylhexanal, 2-acetonyl-3-pentyloxepane is obtained with 95% diastereoselectivity (Equation 30) <1994CC1123>. 

Chloroaniline, 2295 2-Chloronitrobenzene, 2134 4-Chloronitrobenzene, 2135 2(3-Chlorophenoxy)ethylamine, 2971 IV-Chlorosuccinimide, 1423 A-Chlorotoluene-4-sulfonamide, 2793 Dibenzoyl peroxide, 3632... 

The first examples of a direct substitution upon the carbon atoms of the dioxetane core have now appeared (Scheme 9) <1997JA245>. Thus, treatment of alkylthiodioxetane 49 with a slight excess of a Lewis acid oxidant such as iV-chlorosuccinimide (NCS) or mercuric acetate in the presence of excess ROH leads to the formation of oxygen-substituted dioxetanes 50 in low to moderate yields. 

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