Methylene and nitro

A large steric interaction between the bridging methylene and nitro group of the o-complex has been suggested to account for decreased a-reactivity the fused-ortho effect , though analysis of the sterics in bicycloannelated derivatives show this is unlikely (Section 2.1). For discussion of the fused-ort/io effect , see ref. 34a,b. 

Annulation of methylene and nitro groups of 2-arylaminomethyl-3-nitropy-ridine by heating with a primary arylamine in acetic acid leads to the pyrazolone together with a small amount of the corresponding pyrazole in some experiments. 

Anilino-5 -nitroaniline (170) gave 2,3-dimethyl-6-nitro-l-phenylquinoxaIi-nium perchlorate (171) (Ac2, HCIO4, Bu0H-Et20-H20, 20°C, 20 min 84%) and thence 2-methyl-3-methylene-7-nitro-4-phenyl-3,4-dihydroqui-... 

Compounds with methylene and methyne groups to which are attached two electronegative groups, such as carbonyl, alkoxycarbonyl, formyl, cyano, nitro, and sulfonyl groups, react with butadiene smoothly their acidic hydrogens are replaced with the 2,7-octadienyl group to give mono-and disubstituted compounds (59, 60). In addition, branched products are... 

Spurred by these observations, we examined a relevant application of the method for nitrocyclopropane synthesis from nitroalkenes and dimethylsulfoxonium methylide (17), Equation 3. It had previously been employed for the synthesis of a 2,3-dideoxv-2,3-C-methylene-3-nitro-hexopyranoside, the first one of the small number of carhohvdrates containing the nitrocyclopropane structure thus far known (18). 

Plastiques 12, 351(1936) Sc CA 31, 2007(1937) (Detn of DPhA in Guncotton) 7) F. Becker G. Hunold, SS 33, 213 Sc 244(1938) CA 32, 9501(1938) (Detn of DPhA in proplnts) 8) R. Dalbert, MP 28, 119-26(1938) Sc CA 33, 7569-70(1939) (Analytical procedure for detection of DPhA and its nitroso- and nitro- derivs in "poudres B stored at various temps. The method includes extraction with. methylene chloride and conversion of nitroso- and nitro-derivs into amine using stannous chloride and H.C1) 9) Clift Sc Fedoroff 1(1942), Chap XII,... 

M. Funabashi, H. Wakai, K. Sato, and J. Yoshimura, Branched-chain sugars. Part 15. Synthesis of l-i.-(l,2,3, 4,5/3,6)-3-hydroxymethyl-4,5-0-isopropylidene-3,3 -0-methylene-6-nitro-2,3,4,5-tetrahydrocyclohexanecarbaldehyde dimethyl acetal, a potential key compound for total synthesis of optically active tetrodotoxin, J. Chem. Soc. Perkin Trans, p. 14 (1980). 

Vinylpyrroles and vinylindoles are extremely sensitive to acid-catalyzed dimerization and polymerization and it is significant that much of the early research was conducted on systems which were produced in situ. Even by this approach, the dimerization of, for example, 2-(3-indolyl)propene and l-(3-indolyl)-l-phenylethylene was difficult to prevent (see the formation of 110 and 120, Section 3.05.1.2.8). Similarly, although it is possible to isolate ethyl 2-(2- and 3-indolyl)propenoates, they appear to be extremely unstable at room temperature even in the absence of acid (81UP30500) to give [ 4 + 2] cycloadducts of the type (348) (cf. 77JCS(P1)1204>. For many years simple vinylpyrroles also eluded isolation, on account of their facile acid-catalyzed polymerization. Application of the Wittig reaction, however, permits the synthesis of vinyl-pyrroles and -indoles under relatively mild and neutral conditions (see Section 3.05.2.5). In contrast, heteroarylvinyl ketones, esters, nitriles and nitro compounds, obtained by condensation of the appropriate activated methylene compound with the heteroaryl aldehydes (see Section 3.05.2.5), are thermally stable and... 

When either of the unsubstituted nitrodesoxy sugars was treated with mild alkali, intramolecular condensation of the carbonyl and nitro-methylene functions occurred to give a complex mixture of optically-inactive nitrodesoxy inositols.61 68 The ring closure in each instance might be expected to give four diastereoisomers, since two new asymmetric centers are produced, at carbons one and six. However, the... 

Clemmensen-type reduction.1 Aromatic ketones can be reduced to the corresponding methylene compounds with ammonium formate on transfer hydrogenation in acetic acid catalyzed by 10% Pd/C. The reduction is usually complete in 10-30 minutes at 110°. Halo and nitro substituents can be reduced under these conditions, and a,p-unsaturated carbonyl groups are reduced to saturated carbonyl groups. 

Utilized selective anisotropic solvent adsorption on specific crystal faces to favour the growth of morphologically polar crystals. Some additional reports of the study of crystal modification and nonlinear optical activity include those on anhydrous and hydrated sodium / -nitrophenolate (Brahadeeswaran et al. 1999), derivatives of 2-benzylideneindan-l,3-dione (Matsushima et al. 1992), straight-chain carbamyl compounds (Francis and Tiers 1992), benzophenone derivatives (Terao et al. 1990), a 1,3-dithiole derivative (Nakatsu et al. 1990), o -[(4 -methoxyphenyl)methylene]-4-nitro-benzene-acetonitrile (Oliver et al. 1990) and so-called lambda shaped molecules (Yamamoto et al. 1992). Hall et al. (1988) followed the thermal conversion of the centrosymmetric P2 /c) form of 2,3-dichloroquinazirin to the non-centrosymmetric Pc form by monitoring the development of an SHG signal. Consistent with the earlier observation, the centrosymmetric form was obtained under equilibrium conditions, while the non-centrosymmetric one could be obtained under more kinetic conditions. 

Oliver, S. N Pantelis, P. and Dunn, P. L. (1990). Polymorphism and crystal-crystal transformations of the highly optically nonlinear organic compound q -[(4 -methoxyphenyl)methylene]-4-nitro-benzene-acetonitrile. Appl. Phys. Lett, 56, 307-9. [213]... 

The methylene group of methyl ethyl ketone is active in the condensation to give, upon pyrolysis, only methyl isopropenyl ketone (92%). Olefinic aldehydes, acids, esters, and nitro compounds have been prepared in a similar manner. The literature of the Mannich reaction has been reviewed. ... 

The method has been adapted to the formation of l)fs-diazoacetylalkanes from dibasic acid chlorides. Diazo ketones have been obtained from acyl chlorides containing a /Sj y-double bond, an ester group, and certain heterocyclic and aryl nuclei having alkyl, methoxyl, and nitro substituents. On the other hand, functional groups such as phenolic hydroxyl, arylamino, aldehyde, active methylene, and a,/S-unsaturated linkages may interfere. The method is ideal for application to complex molecules. 

The methylene, cyano and nitro groups of compound (72.2) are involved in its conversion to an isoindole derivative by heating with a catalytic amount of ethanolic potassium acetate. 

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