P-Nitrobenzenesulfonyl chloride

The much-used sulfonylation by aromatic sulfonyl chlorides is illustrated by the conversion of quinazolin-4-amine into the sulfonamide (247) using p- nitrobenzenesulfonyl chloride at 60 °C (56JCS3509). 

The procedure given is applicable to many other aulfonyl chlorides as well (see Table I). Solid sulfonyl chlorides are added as such. When heavy frothing occurs in the reduction (e.g., with p-nitrobenzenesulfonyl chloride), addition of 50 ml. of chloroform to the reaction mixture will eliminate the foam without reducing the final yield. When the sulfonyl chlorides were prepared according to Meerwein and co-workers, it was found advantageous to use the crude, damp sulfonyl chlorides, since these are more easily reduced than the dried or recrystallized materials. 

The classic syntheses of the antibacterial sulfonamides involve reaction of the appropriate arylamine with an acid addition salt of p-amino-benzenesulfonyl chloride, or p-nitrobenzenesulfonyl chloride followed by reduction. Chemical interest largely resides in preparation of the corresponding arylamines. For the synthesis of sulfacytine (134), N-ethyl uracil (131) was converted to its thioamide (132) by reaction with phosphorous pentasulfide. The newly introduced sulfur is then displaced with ammonia in methanol to give 133. Standard reactions complete... 

The reagent is prepared by reaction of p-nitrobenzenesulfonyl chloride with 4-nitroimidazole (triethylamine). ... 

To a 3 L, three-neck flask equipped with a stirrer, thremometer, and condenser was charge 30.0 g (0.24 mole) of 3-azabicyclo[3.2.2]nonane, 44.3 g (0.2 mole) of p-nitrobenzenesulfonyl chloride and 2 L of water. The pH of the reaction mixture was adjusted to 14 with a 10% solution of sodium hydroxide the reaction mixture was then slowly heated to 75°C and heating stopped. 

Guanidine hydrochloride Hydrogen chloride p-Nitrobenzenesulfonyl chloride... 

This starting material can be prepared as follows. 123 parts of finely powdered 6-amino-2,4-dimethylpyrimidine are suspended in 250 parts of dry pyridine and 222 parts of p-nitrobenzenesulfonyl chloride added at 50°C to 55°C. The whole is then warmed for 2 hours to 55°C. Water is added to the crystalline aggregate obtained, the precipitated bis-N-(p-nitrobenzenesulfonyl)-6-amino-2,4-dimethylpyrimidine filtered off by suction and washed with water. It is purified by recrystallizing from methyl ethyl ketone. On slowly heating it decomposes on rapidly heating it melts at about 210°C to 215°C with decomposition. 

Nitrobenzenediazonium fluoroborate, 166 p-Nitrobenzenesulfonoxyurethane, 736 m-Nitrobenzenesulfonyl chloride, 449 p-Nitrobenzenesulfonyl chloride, 736 p-Nitrobenzoic acid, 286,317,666, 866,901, 1060... 

P-Nitrobenzenesulfonyl chloride, 16,55 -Nitrobenzoic acid, 16, 87 Nitrobenzoyl chloride, 17,93 Nitrobenzyl bromide, 16, 64 o-Nitrochlorobenzene, 14, 67 Bt-Nitrochlorobenzene, 10,112 Nitrochlorobenzene, 14, 66 o-Nitro- - chlorophenylsulfur chloride, 15,45... 

Subtle differences in acidity can sometimes be used to discriminate between two hydroxyl functions (Scheme 58). In these cases, p-nitrobenzenesulfonyl chloride appears to be the reagent of choice. Not only does it display improved chem-oselectivity for the most acidic hydroxyl function, but it also acts as a better leaving group. This strategy was employed to prepare, inter alia, substituted a-ami-no acids 225 [127a],glycidic esters 226 [127a] and chloramphenicol 227 [139]. 

Materials 2-Aminopyrimidine p-Nitrobenzenesulfonyl chloride Iron Hydrogen chloride ... 

The peroxide is prepared by oxidation of p-nitrobenzenesulfonyl chloride with 307 H2O2 (C2H5OH. H2O, KzCOo) yield, 40%. 

Benzenesulfonhydroxamic acid allowed to react with p-nitrobenzenesulfonyl chloride and 3-4 moles triethylamine N-p-nitrobenzenesulfonyloxybenzene-sulfonamide. Y 93%. F, e. s. M. Okahara and D. Swern, Tetrah. Let. 1969, 3301. 

Asymmetric sulfonylation was also developed by Miller employing tetra-peptide catalyst 42. ° Desymmetrisation of a variety of meso-l,3-diols was examined. Asymmetric sulfonylation of rwyo-inositol derivative 35 with p-nitrobenzenesulfonyl chloride (p-NsCl) (43) as a sulfonyl donor in the presence of catalyst 42 gave monosulfonylated product 44 in high yield and enantiomeric excess (76% yield with 94% enantiomeric excess) (Scheme 22.9). 

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