Nitro sulfonation

Geminal dinitro compounds, " ct-nitro sulfones, " ct-nitro esters, or ct-nitro nitnles react v/ith anions derived from nitro ilkanes to give the Spj l products, as shovmin Eqs. 5.28, 5.29, 5.30 and 5.31, respecdvely fSecdon 7.1. ... 

Tin radicM-induced eliminadon from fi-nitro sulfones or fi-nitro sulfides proceeds in a stereoselecdve way to give ruin eliminadon products. " Whendiastereoraers of fi-nitro sulfones can be separated, each diastereoraer gives (Ey and fZ -alkenes selecdvely fEq. 7.111. Such... 

Nitrosylsulfuric Acid (Nitroso, Nitrosyl Sulfate, Nitrosulfuric Acid, Nitroxylsulfuric Acid, Nitro-sulfonic Acid, Nitrosyl Hydrogen Sulfate, Nitro Acid Sulfite). HNOs S, NO HS03, HNOS04, ONOSO3H, mw 127.08, N 11.02%, colorl prisms mp, decomps 73.5°. In moist air the crysts decomp with the formation of sulfuric and nitric... 

The transformation of l-methylthio-l-(methylsulfonyl)alkanes (254) to methyl esters can be efficiently carried out by oxidation or by a-chlorination followed by methanolysis (equation 152)145. The lithium or the sodium salt of (phenylsulfonyl)nitromethane (256) is a very useful reagent for the preparation of higher homologues of nitromethanes by alkylation since the salts are air insensitive, non-hygroscopic, and easily handled without decomposition. The oxidation of the resulting secondary a-nitro sulfone (257) gives... 

The conversion of secondary a-nitro sulfones (257) upon treatment with 20% aqueous titanium(III) chloride in THF to nitriles has been reported (equation 157)146. 

Nitro compounds that contain an a hydrogen can be reduced to oximes with zinc dust in HOAC or with other reagents, among them CS2—Et3N, CrCl2, " and (for a-nitro sulfones) NaN02. oc-Nitro alkenes have been converted to oximes... 

Wade and coworkers have found that a-nitro sulfones are useful reagents in organic synthesis because they are converted into nitroalkanes, nitriles, or carboxylic acids (see Eq. 5.52).76... 

Phenylsulfonyl)nitromethane is preferentially C-alkylated by ally lie acetates in the presence of Pd(PPh3)4 (5 mol%) to give various a-nitro sulfones as shown in Eq. 5.53.76... 

The reaction of a-bromo or a-iodonitroalkanes with sodium benzenesulfinate gives a-nitro sulfones in 85-95% yields (Eq. 5.73), which proceeds via SRN1 reaction (Section 5.4).117... 

Tin radical-induced elimination from P-nitro sulfones or P-nitro sulfides proceeds in a stereoselective way to give anti elimination products.153 When diastereomers of P-nitro sulfones can be separated, each diastereomer gives ( )- and (Z)-alkenes selectively (Eq. 7.111). Such... 

Oxidation may be achieved in the presence of oxygen or air. Other suitable oxidants include sulfur, sodium polysulfide, iron (III) chloride, potassium ferro-cyanide (III) or potassium dichromate, peroxydisulfate or salts of aromatic nitro-sulfonic acids. An aqueous/alkaline medium is used in the presence of a high boiling organic solvent which is not miscible with water or which is almost immiscible with water. Cyclization with chlorosulfonic acid can be followed directly by oxidation with bromine to afford the thioindigo system, without separation of the intermediate. 

Eine Mischung aus I0 mmol a>Nitro-sulfon und 30 mmol BNAH in N2-freicm DMF werden bet 20 unter Stickstoff geriihrt b Ausbeute durch GC besttimmt B isolierte Ausbeute... 

The bishydrazones of the 1,2-diketones from inositols have also been converted into triazoles.222,223 The conversion of arylosazones into the corresponding osotriazoles requires the presence of an oxidant, and it is obvious that simple removal of aniline from the osazone, as suggested by the equation, is not involved. In addition to copper(II) sulfate, the reagent most commonly used, other oxidizing heavy-metal salts, such as ferric sulfate and chloride,224 and mercuric acetate,223 have been used, as well as halogens225 and nitro-sulfonates.226 The osazone acetates are converted into osotriazoles by nitrous acid,227 which decomposes the unacetylated osazones to the aldosuloses228 and the osazone formazans are cyclized with warm... 

Substituent effects follow the general pattern of substituted benzene derivatives in that nitro, sulfonic acid, and carboxyalkyl groups deactivate the ring to further substitution, whereas amino and methoxy groups strongly activate, and methyl and chloro groups have little effect. Ridd383 has recently reviewed electrophilic substitutions on quinoline, pyridine, and imidazole. 

In 1991, Goff et al reported synthesis and activity testing of monoquatemary imidazole derivatives with various substituents sueh as ether, silicone, nitrile, ester, halogen, nitro, sulfone or amino group (Goff et al, 1991). Published literature reveals that syntheses started from 1-methyl-imidazole (Figure 66.5). 

All the synthesized compounds were tested both in vivo on mice intoxieated by soman or tabun and in vitro on human erythrocyte AChE. In conclusion, nitro, sulfone, amino, and aminosulfonyl side-chain substituents caused high antidotal activity, where the optimum length of side-... 

Koolpe, G.A., Lovejoy, S.M., Goff, D.A., Lin, K.Y., Leung, D.S., Bedford, C.D., Musallam, H.A., Koplovitz, L, Harris, R.N. (1991). Quaternary salts of 2-[(hydroxyimino)methyl]imidazole. 5. Structure-activity relationships for side-chain nitro-, sulfone-, amino-, and aminosulfonyl-substituted analogues for therapy against anticholinesterase intoxication. J. Med. Chem. 34 1368-76. 

Cyanoborohydride and its modified reagents have been used for reductive dehalogenations. Thus, the combination of sodium or tetrabutylammonium cyanoborohydride, sodium or potassium 9-cyano-9-hydro-9-borabicyclo[3.3.1]nonanate [9-BBNCN] (2) or polymeric cyanoborane (3) in HMPA furnishes an efficient and mild system for the reduction of alkyl halides. The reagents are selective in that other functional groups, including ester, carboxylic acid, amide, cyano, alkene, nitro, sulfone, ketone, aldehyde and epoxide, are essentially inert under the reduction conditions thus, the reduction procedure is attractive for synthetic schemes which demand minimum damage to sensitive portions of the molecule. 

A major drawback to the 1,2-dinitroalkane approach to tetrasubstituted alkenes is its poor stereoselectivity. Thus treatment of the erythro- and rlireo-1,2-dinitroalkanes (112 and 113 Scheme 40) respectively with BuaSnH in refluxing l nzene gave the alkene as a 1 1 mixture of isomers. By contrast, the reductive elimination of certain 3-nitro sulfones is stereospecific because the elimination of the radical intermediate is faster than bond rotation. For example, treatment of the 3-nitro sulfones (114) and (116) with BuaSnH gave the alkenes (115) and (117) with high efficiency and stereoselectivity (equations 27 and 28). 

The synthesis of the requisite P-nitro sulfones is accomplished by reacting a carbanion stabilized with a cyano and arylsulfonyl group with a 1-bromonitroalkane, as shown in equation (29). Carbanions stabilized by one arylsulfonyl group or by an arylsulfonyl and nitro group do not react. 

Sodium perborate in warm glacial acetic acid will oxidise simple alkyl and aryl sulfides, and amino sulfides, (75) are converted to the corresponding nitro sulfones (76) (Scheme 29). 

---