7V-chlorosuccinimide

Scheme 22. a) CHCI3, pyridine, 7V-chlorosuccinimide, TEA. b) Mn02, benzene, reflux, c) TBAF, CH2CI2... 

More readily carbamoylation of 1-morpholinocyclohexene with 1-naphthyl isocyanate gave a mixture of isomeric 2-morpholino-A -(l-naphthyl)cyclohex-l(or2)-ene-l-carboxamide in 85% yield. Successive treatment with 7V-chlorosuccinimide (NCS) in acetonitrile gave 3-chloro-2-morpholino-iV-(l-naphthyl)cyclohex-l-ene-l-carboxamide (21) in 74% yield. 

Ethyl 3-amino-6-hydroxyiminomethyl-2-pyrazinecarboxylate (311) gave a solution of the carbonitrile oxide (312), and thence the cycloadduct, 3-(5-amino-6-ethoxycarbonylpyrazin-2-yl)-3a,4,5,6a-tetrahydrofuro[3,2-t/]isoxazole (313) [7V-chlorosuccinimide, Me2NCHO, 60°C, Nj, 3 h then 2,3-dihydrofuran J, EtjN J, 2 20°C, 3 h 55%).8 ... 

The alcohol (1.5 L, 208 g, 280 mmol) in THF is charged to a jacketed flask followed by dimethyl sulfide (37 g, 590 mmol) and diisopropylethylamine (47 g, 364 mmol). The solution is cooled to approximately -13 °C. 7V-Chlorosuccinimide (NCC 71 g, 532 mmol) is dissolved in THF (240 mL) and added to the flask at a rate so as to maintain the internal temperature at -11 to -13 °C. The mixture is then stirred at -15 5 °C for 3 h. Isopropyl acetate (3 L) is added followed by 0.5 N NaOH (1.2 L). The mixture is warmed to room temperature and stirred for 1 h. The organic layer is washed with 5% NaCl (2 x 600 mL) and brine (2 x 600 mL). The product layer is concentrated under vacuum to obtain, at first, a yellow amorphous solid which when dried under high vacuum turns into a white foam. Slurrying the solid in warm water followed by filtration and drying afforded 196 g (94%) of the 3-ketomacrolide as a white solid after trituration with 10% EtOAc/heptane. 

Many of the reactions which result in ring cleavage have been described in Section 6.19.6.3.3. This section is reserved for those reactions which do not involve nucleophilic attack at a ring carbon. The 1,3,5-dithiazine (88) is cleaved by 7V-bromo- or 7V-chlorosuccinimide to produce the reactive thial 5-sulfide species which dimerizes to the tetrathiane (89) (Scheme 5) <88CL1517>. Compound... 

A -bromosuccinimide gives lower labefing yields and, sometimes, radical side reactions are observed. On the contrary, 7V-chlorosuccinimide in TFA enables direct electrophilic radioiodination, even of nonactivated or... 

Related Reagents. 7V-Bromosuccinimide Chloramine-T 7V-Chlorosuccinimide N-(l, 1-Dimethylethyl)benzenesulfinimi-doyl Chloride Tetrapropylammonium Perruthenate Dimethyl sulfoxide-oxalyl Chloride l,l,l-Triacetoxy-l,l-dihydro-l,2-benziodoxol-3(l/7)-one 2-Iodoxybenzoic Acid (IBX) Diphenyl Sulfoxide. 

Preparative Methods by chlorination of methyl phenylth-ioacetate using sulfuryl chloride or 7V-chlorosuccinimide (NCS) methyl phenylthioacetate (16.8 g) is stirred with powdered NCS (13.3 g) in CCI4 at rt for 10 h, the mixture filtered, the filtrate evaporated, and the residue distilled using a short Vigreux column. ... 

Trimethylsilyl halides can also be used for analogous reactions with arenediazo-nium tetrafluoroborates, as shown by Keumi et al. (1989). These authors treated 2-fluorenediazonium tetrafluoroborate in A/,Af-dimethylformamide or -acetamide with trimethylsilylchloride, -bromide, or -iodide in the presence of an excess of N-chlorosuccinimide, Af-bromosuccinimide, or methyl iodide, respectively, at 60 °C (Cl, Br) or at room temperature (I). The yields of the 2-halofluorenes were good in addition fluorene, the product of hydro-de-diazoniation, was obtained, if the reaction was run in tetrahydrofuran/Af,7V-dimethylformamide mixtures. The mechanism of these reactions, as well as that of the corresponding azido-de-diazoniation, is uncertain (see also Secs. 10.2 and 10.7). 

Phenyl- and 2-methyl-6-phenyldihydrodiazepinium salts are haloge-nated at the p-position of the phenyl groups by N-bromo- and N-iodosuc-cinimide but not by A/-chlorosuccinimide, whereas the 1,4-dimethyI-6-phenyl derivative reacts only with the 7V-bromosuccinimide [81JCS-(PD726]. 

Tellurium bis[dithiocarboxylates] lose one dithiocarboxylate group and form tellurium dithiocarboxylate halides in reactions with equimolar amounts of chlorine, bromine, iodine, iV-chlorosuccinimide, or 7V-bromosuccinimide in dichloromethane. ... 

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