Nitromethane as solvent

Furthermore, Jana et al. developed a FeCl3-catalyzed C3-selective Friedel-Crafts alkylation of indoles, using allylic, benzylic, and propargylic alcohols in nitromethane as solvent at room temperature. This method can also be used for the alkylation of pyrrole (Scheme 4). The reactions were complete within 2-3 h without the need of an inert gas atmosphere leading to the C-3-substitution product exclusively in moderate to good yields [20]. 

The catalytic application of clays is related closely to their swelling properties. Appropriate swelling enables the reactant to enter the interlamellar region. The ion exchange is usually performed in aquatic media because the swelling of clays in organic solvents, and thus the expansion of the interlayer space, is limited and it makes it difficult for a bulky metal complex to penetrate between the layers. Nonaqueous intercalation of montmorillonite with a water-sensitive multinuclear manganese complex was achieved, however, with the use of nitromethane as solvent.139 The complex cation is intercalated parallel to the sheets. 

Although in most reported examples the yields in Nenitzescu condensations range between 20-50%, the yields are strikingly improved by use of nitromethane as solvent and are better for (3 -methoxycarbonylenamines than for the corresponding ethyl esters (79TL4009). 

During synthetic studies on the antitumour antibiotic CC-1065, ready access was required to a series of 6-substituted indole-3-carboxylates. The following example illustrates the successful general strategy that was developed reaction of the N-Cbz derivative of N-(3-methylphenyl)hydroxylamine with methyl propiolate in nitromethane as solvent and in the presence of Hunig s base gave methyl l-benzyloxycarbonyl-6-methylindole-3-carboxylate directly in 89% yield. 

Phosphorus(III) isocyanate was first prepared by the reaction of phosphorus(III) chloride with silver isocyanate in warm benzene.1 A later modification utilized phosphorus(III) iodide as a starting material with nitromethane as solvent.2... 

The 9-phenyl-9-fluorenyl (PhFl, 118, Scheme 56) amino-protecting group has been proposed by Christie and RapoportF as it is significantly more stable to solvolysis in acid conditions than the trityl group because of the antiaromatic character of the fluorenyl cation. In fact, solvolysis of Trt-Cl is 6000 times faster than PhFl-Cl.f The AI -PhFl amino acid derivatives are prepared with PhFl-Br (commercially available or prepared from fluorenone and phen-yUithium and subsequent substitution with HBr) and lead nitrate, which is required to trap the bromide (Scheme 56).F f2i] lead-free alternative using nitromethane as solvent has also been reported. ... 

Ammonium salts with two different alkyl chains were prepared directly via subsequent alkylations of dimethylamine with primary bromides and crystallization. Commercial hexadecyl-methylamine can be conveniently applied in the same way in order to convey functionality to cationic synkinons. A recent example describes subsequent alkylations with a small functional and a long-chain primary bromide (Scheme 2.4). A-acylated / -phenylenediamine was also alkylated at the second nitrogen atom which had two different alkyl chains, with or without extra functionality . After deacylation, this head group can be diazotized or coupled oxidatively with various heterocycles in water (Scheme 2.4). Photoactive and coloured membrane surfaces are thus obtained. Phenylene-diamine, pyridine and in particular A-methyl-4,4-bipyridinium chloride are relatively weak nucleophiles. Substitution of bromides is slow and the more reactive iodides can rarely be obtained commercially, but the selection of nitromethanes as solvent for bromide substitution is of great help as well as the addition of sodium iodide to enforce a Finkelstein reaction or a combination of both. 

Under homogeneous conditions, with the use of nitromethane as solvent, the reaction of 1,2,3-trichlorocyclopropenylium tetrachloroaluminate (1) with 0.5 equivalents of alkenes 11 at — 35 C exclusively afforded l-alkyl-2,3-dichlorocyclopropenylium ions 12, which wereisolable as the 2-alkyl-l,3,3-trichlorocyclopropenes 13. The latter were transformed into a-methyl-ene-y-butyrolactones in fair to good yields. 

Recrystallization from boiling MeOH (15 mL/g) yielded, after filtration and air drying, beta-nitro-3,4,5-trimethoxystyrene as bright yellow crystals weighing 18.5 g. An alternate synthesis was effective, using an excess of nitromethane as solvent as well as reagent, if the amount of ammonium acetate catalysis was kept small. 

When thermolysis of benzothiepines (71c,d) is carried out in the presence of cyclohexene sulfide in carbon tetrachloride or nitromethane as solvent, the desulfuration products (73c,d) together with an equimolar amount of cyclohexene are produced. This behavior leads to the assumption of S2-species as the primary elimination product of sulfur from the thianorcaradiene intermediate K (see Section 9.03.4.2) (Scheme 12) <90ZN(B)1059>. 

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