Nitro-styrenes

Hydroxybenzaldehydes readily react with compounds containing methyl or methylene groups bonded to one or two carboxyl, carbonyl, nitro, or similar strong electron-withdrawing groups. The products are usually P-substituted styrenes. 4-Hydroxybenzaldehyde, for example, reacts with 2-methylquinazolines (where R = H, Cl) to give compounds which have anti-inflammatory activity (59). 

In contrast to other furoxans, the cycloreversion of 3,4-dinitrofuroxan to nitro-formonitrile oxide was observed even at room temperature. The nitrile oxide could be trapped in situ with electron-deficient nitriles (Scheme 149) (95MC231). Attempts to obtain cyclo adducts with styrene, phenylacetylene, rran.s-stilbene, and cyclohexene failed. 

As shovm in Eq 6 59, Rapoport has prepared sinefungin, nucleoside andbiodcs, via nitro-aldol reaction, dehydradon, and reducdon v/iihZn in acetic acid fi-Niiro styrenes are selecdvity reduced to the corresponding oximes by indium metal in aqueous methanol under neutral conthdons ... 

With Pd(dba)2 in acetone/dichloromethane (1 1) and ethene (6-8 atm), styrene is formed from benzenediazonium tetrafluoroborate in 51% yield with seven substituted benzenediazonium salts the yields were 62-75%, but very small yields were obtained with the 2,4,6-trimethyl and the 2- and 4-nitro derivatives (Kikukawa et al., 1979). The two nitrodiazonium salts are good substrates in the Meerwein reaction... 

Bartlett and co-workers concluded that addition to the nitro group also occurs. Price and Read found that several m-dinitrobenzene molecules were combined with the polymer for each fragment from the p-bromobenzoyl peroxide used as initiator in the retarded polymerization of styrene. They inferred that the radical corresponding to IV transfers its hydrogen atom to a molecule of styrene as follows ... 

The hydrothiolation of electron-deficient alkenes [X = CN, C(=0)(0Me)] and p-nitro-styrene was catalysed by the Cu complexes 98 and 99. The reactions with phenyl- or benzyl-thiol proceed with high conversions (>90%, rt, 5 mol%). 

A useful application in the manufacture of ion-exchange resins may well be possible which avoids the use of carcinogenic chloromethyl ether. Here, a polymer of p-methyl styrene is chlorinated on the side chain with aqueous NaOCl and a phase-transfer catalyst. Sasson et al. (1986) have shown how stubborn . substituted aromatics like nitro/chlorotoluenes can be oxidized to the corresponding acids by using aqueous NaOCl containing Ru based catalyst. 

B. m-Nitrostyrene. In a 250-ml. two-necked flask equipped with a 250° thermometer and an air condenser are placed 30 g. (0.155 mole) of m-nitrocinnamic acid, 2 g. of copper powder, and 60 ml. of dry quinoline (Note 3). The flask is heated with a Bunsen burner to 185-195°, during which time a steady stream of carbon dioxide is evolved. After 2-3 hours (Note 4), the reaction mixture is cooled and poured into a mixture of 75 ml. of concentrated hydrochloric acid and 175 g. of ice. The m-nitro-styrene is isolated by steam distillation, approximately 1 1. of... 

This procedure has been used in the preparation of other nitrostyrenes in the following yields o-nitrostyrene (40%),2 / -nitrostyrene (41%),2 and 3-nitro-4-hydroxystyrene (60%).2 A better procedure for more volatile styrenes involves simultaneous decarboxylation and codistillation with quinoline from the reaction flask. This method has been used to prepare the following styrenes o-chlorostyrene (50%),3 4 m-chlorostyrene (65%),4 -chlorostyrene (51%),4 m-bromostyrene (47%),4 o-methoxystyrene (40%),4 -methoxystyrene (76%),4 m-cyano-styrene (51%),3 and j -formylstyrene (52%).9... 

The reaction tolerated a variety of functionality, including ester and ether groups on the alkyl-substituted alkene at least two carbons away from the double bond, and raefa-nitro or para-methoxy substituents on the styrene. As expected, cross-metathesis occurred selectively at the less hindered monosubsti-tuted double bond of dienes also containing a disubstituted alkene (Eq. 8). 

Illustrated for 5,6,7-trimethoxyindole (for the trimethyl-indole see JOC 25,1542(1960)). 2-methoxy-beta-nitro-styrene, if nitrated at the 6 position and used in place of (I), should give 4-methoxy-indole. 

Al-Nitrosodiethanolamine, 2 449, 450 Nitroso dyes, 9 263-264 Nitro soluble dyes, 7 373t Nitroso soluble dyes, 7 373t Nitrosomonas, use in recirculating aquaculture biofiltration, 3 196 P-Nitrostyrenes, preparation by nitration of styrenes, 16 581 Nitrosyl chloride, 20 634 Nitrosyl complexes, osmium, 19 642 Nitrosyl perchlorate, 18 279 Nitrosyl tetrafluoroborate, 4 144t n-Nitrotoluene, 17 263... 

The seminal work on deep-UV resist materials which incorporate chemical amplification was started at IBM San Jose s Research Laboratory in 1979 when FrSchet and Willson first prepared poly(4-t-butyloxycarbonyloxy styrene) and end-capped copolymers of o-phthalaldehyde and 3-nitro-l,2-phthalic dicarboxaldehyde. 

Methylmethacrylate CH2 = C(CH3)COOCH3 a-methyl styrene CH2 = C(CH3)C6H5 Styrene CH2 = CHC6H5 Nitro ethylene CH2 = CHN02 p-nitro styrene CH2 = CHC6H4N02 Tetrafluoro ethylene F2C = CF2 Vinyl acetate CH2 = CHOCOCH2 Vinyl carbazole CH2 = CH(C12H8N)... 

A similar formation of indoles has been achieved starting from o-nitro-styrenes. Under hydroformylation conditions, the nitro group is reduced to the amino group, which condenses with the in situ generated aldehyde [48].This approach is comparable with the indole syntheses of Reis-sert [49], Batcho and Leimgruber [50], and Sugasawa [51]. 

Scheme 3.7 Two alternative reaction routes for the organocatalytic Michael addition of acetylacetone to nitro styrene.

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