Nitrosulfone

Phenylsulfonyl)nitromethane is preferentially C-alkylated by benzylic halides and primary alkyl iodides, affording secondary a-nitrosulfones . 

At room temperature under photostimulation a-nitrosulfones react with a variety of nucleophiles via radical anion chain reactions interestingly, in none of the cases where the PhSOj group is involved in SrnI type of substitution does the O end of the ambident anion " play a role. This strong regioselectivity is reminiscent of the one reported for other ambident anions involved in these radical chain substitutions. ... 

The production of olefines from p-nitrosulfones provides another type of effect of the chemical additives. The reaction is conducted in DMF without light irradiation using sodium sulfide as a reactant. The olefin forms in 97% yield (Ono et al. 1980, 1983). 

The thiadiazepine 301 has been already reported <1992SC1433> and thiadiazepine 302-318 and 319 were obtained by the alkylation of 301 with alkyl halides. The chloro derivatives 321-327 and 329-335 were obtained from 320 and 328, respectively, which in turn were synthesized by the intramolecular cyclization of the corresponding aminosulfones 298-300 (Scheme 68). These aminosulfones were obtained by the reduction of nitrosulfones 295-297 <1996BMC837>. 

Reaction of the a-nitrosulfones (2) with aqueous TiCl3 results unexpectedly in nitriles, RC=N, in about 75% yield, a-Nitrosulfones are oxidized in alkaline solution by excess KMn04 to carboxylic acids, RCOOH, in 80-90% yield, probably via the acyl sulfone. 

The ,/J-LinsaUirated-o -nitrosulfone intermediate, 113, in the tandem nitroaldol/ dehydration reactions was successfully intercepted with various thiols, 117, added to the reaction mixture prior to the addition of aldehyde, 118. In four cases examined, little if any of 112 was formed. The initial products 119-122 were a mixture of diastereomers, although after crystallization, a single diastereomer was obtained in each case with good yields (Scheme 39). 

It is to be observed that other m-nitrosulfonic acids also form very insoluble fenous salts. One example is 2-nitro-4,8-naphthalenedisulfonic acid wmch can be obtained in a pure state very easily by this method. This method of separation has long been known in the industry. For information about 2-naphthylamine-4,8-disulfonic acid, see page 219 ff. 

The sulfite formed can exert a reducing action when easily reducible groups are present. For this reason, alkali fusion of nitrosulfonic acids rarely works well. Sometimes this redudng action can be counteracted, especially in the anthra-quinone series, by the addition of an oxidizing agent or an all ne earth hydroxide in the latter case, the sulfite is precipitated as an insoluble salt and thus rendered harmless. 

In the laboratory of B.M. Trost, the second generation asymmetric synthesis of the potent glycosidase inhibitor (-)-cyclophellitol was completed using a Tsuji-Trost allylation as the key step. The synthetic plan called for the conversion of the a-nitrosulfone allylation product to the corresponding carboxylic acid or ester. Numerous oxidative Nef reaction conditions were tested, but most of them caused extensive decomposition of the starting material or no reaction at all. Luckily, the nitrosulfone could be efficiently oxidized with dimethyidioxirane under basic conditions (TMG) to afford the desired carboxylic acid in high yield. 

Formation of hyponitrous acid (H2N2O2) from the acid-catalyzed hydrolysis of nitrosulfonic acid. 

Reaction of nitrosulfonic acid with nitrous acid to form sulfates and liberate NO. 

Figures 1-4, 5, and 6 show the time-resolved concentration of species in a batch reactor at various pH s, temperatures, and initial partial pressures of SO2 and N0X for the first 2 and 24 hours respectively. The gas-to-liquid ratio (G/L) is 75. Figure 1 (at Ps02 = 1000, Pjjo = 450, and PNO2 = 50 ppm, pH = 5, and T = 328K) demonstrated that the removal efficiency of NO is only about 10%, although NO2 can be removed nearly completely. This is because NO alone cannot be converted into nitrous acid. The major product is HADS within the initial 1-1/2 hr the concentrations of HAMS and sulfate increase while that of HADS decreases as the reaction time continues. If the reaction is allowed to continue, the final products will be NH4+, N2, and sulfate. Because we disregard the reaction of HAMS and HA with HNO2 and the hydrolysis of nitrosulfonic acid, no N2O is formed.

The lability of the bromine in l-bromopyrrolo[l,2-a]quinoxaline (101) makes the reaction of the nitrosulfonic acid 109 more complex in both concentrated hydrobromic acid and in DMF containing lithium bromide. In the reaction of 109 with lithium bromide the l-bromo-3-sulfonic acid 112 may be isolated after 10 min. However after 1 hr only the 3-bromo compound 100 is obtained. It was also shown that the intermediate 112, as well as the 1-bromo compound 101 and l,3-dibromopyrrolo[l,2-a]quinoxaline, form the 3-bromo compound 100 on reaction with lithium bromide in DMF. ... 

In a recent asymmetric synthesis of cyclophellitol, Trost employed a Nef reaction for the conversion of nitrosulfone 46 to carboxylic acid 47.26 As shown below, 46 was treated with tetramethylguanidine to generate a nitronate salt, which was then oxidized with DMDO to afford the acid in 78% yield. The adjacent double bond was not epoxidized under these conditions. 

EINECS 231-964-2 Lead chamber crystals Nitro acid sulfte Nitro-sulfonic acid hlitrose Nitrososulfuric acid Nitrosulfonic acid Nitrosylsulfuric acid Nltrosylsulphuric acid Nitroxylsulfuric acid Sulfuric acid, monoanhydride with nitrous acid UN2308 Weber s acid. Used to bleach flour. Crystals dec 73°. 

The self-condensation of 410 was observed independently by Bordwell et al. and Davies et al. in 1951-1952.1,9,150 It was indicated that the 6-nitro derivative of 410 does not undergo self-condensation. However, Davies and Porter151 have since found that 410 (acting as a diene) will condense with its 6-nitro derivative (acting as a dienophile) and that dimerization will occur with the 4- and 5-nitrosulfone isomers. Some of the transformations that they reported are presented in Scheme 34 (for the 5-nitro system). The oxidation of 437 to 438 was accompanied by the formation of a trace of... 

To avoid the B-elimi nation neopentyl alkyl sulfonates were subjected to the alkyl nitration. The results summarized in Table XI indicate that the yields of nitration decrease with lengthening of the chain. To obtain optimun yields of a-nitrosulfonate esters containing 8-12 carbons in the chain more concentrated reaction mixtures had to be employed (instead of 250 ml, only 100 ml of liquid ammonia was used). In the case of the C-]2"Sulfonate the yield was only 3% when the nitration was carried out in 250 ml of liquid ammonia. The yield increased ten-fold to 33% when the reaction was performed in only 100 ml of ammonia. It is likely that the low yield was due to a slower rate of anion formation. In fact the yield was increased from 33% to 47% when the anion of the Ci2 Sulfonate was generated with KNH2 in THF at 65° and then nitrated at -40. The Ci6-sulfonate did not undergo nitration at all. This was due to a lack of anion formation. Even when the compound was treated with KNH2 in THF at 65 , no deuterium was... 

ALKYL NITRATE NITRATION OF NEOPENTYL SULFONATE ESTERS Neopentyl 1-nitrosulfonate ester... 

Solid-phase supports used in combinatorial chemistry were used to prepare a cross-linked polystyrene bead containing a tetraethylene glycol spacer. The p-nitrosulfonate derivative of the polymer was substituted with NaCsHMesEt to form a supported cyclopentadiene, which was allowed to react with CpTiCls, making a tethered titanocene (Scheme 26). ° With MAO, this polymerizes ethylene with relatively low activity (41 g/mmol catalyst h) forming polymer with a noodle-like morphology. 

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