Methyl picric acid

Methyl picric acid (heavy metal salts of)... 

Methyl picric acid Methylamine dinitramine Methylene glycol dinitrate... 

Some less reactive tertiary amines can be mixed with an excess of methyl toluene-/)-sulphonate, m.p. 28 , and the mixture (without a solvent) heated to a much higher temperature. The mixture is allowed to cool, but before solidification occurs, it is thoroughly stirred with ether to extract unused sulphonate, and the insoluble quaternary metho-toluene-/)-sulphonate may then crystallise. If ciystallisation does not occur, dissolve this residue in ethanol and treat one portion with ethanolic picric acid (to precipitate the methopicrate) and another portion with cold concentrated ethanolic sodium iodide (to precipitate the methiodide). (M.ps. of the siilphon.ates, pp. 553 -554.)... 

The indolinol character of eseretholemethine is indicated by the fact that the methiodide on treatment with picric acid yields a diquaternary pierate (m.p. 170°) with the loss of the hydroxyl group. More definite proof is afforded by the oxidation of eseretholemethine with ammoniaeal silver nitrate or potassium ferricyanide, when a dehydroeseretholemethine (oxyeseretholemethine of Polonovski), pierate, m.p. 199°, is produced which is assumed to have formula (VI), since on exhaustive methylation it yields trimethylamine and an unsaturated product (deep-red pierate, m.p. 103°), which absorbs two atoms of hydrogen, forming 5-ethoxy-l 8-dimethyl-S-ethyl-2-indolinone (VII), colourless cubes, m.p. 68°. The... 

Methyl-, 2-isopropyl-, 2,3-dimethyl-, 2-methyl-3-ethyl-, and 3-methyl-2-ethyl pyrrole all form crystalline salts of the corresponding dimers with dry HCl or picric acid in ether variable quantities of noncrystalline material are also produced. The dimers are quite stable even as the free bases. 

Methylpyrrole gives only amorphous polymeric material with HCl or picric acid in ether.In contrast with the pyrroles just mentioned, 2,5- and 3,4-dimethyl-, 2-methyl-5-ethyl-, 3-methyl-4-ethyl-, and 2-methyl-4-ethyl-pyrrole do not form crystalline salts, either monomeric or dimeric, and 2,4-dimethyl- and 4-methyl-2-ethyl-pyrrole form only monomeric salts. The dialkylpyrroles in this latter group all dissolve in aqueous sulfuric acid to form relatively stable solutions (e.g., references 14 and 15). The various tri- and tetra-akylpyrroles are likewise soluble in aqueous mineral acid to form stable solutions, and either do not react with HCl or picric acid... 

In moderately acidic solutions bromocriptine mesilate readily forms ion pairs with anionic dyes such as picric acid, bromothymol blue, methyl orange, which are extractable with an organic solvent. A procedure has been developed both for direct assay and for assay following chromatographic separation from the impurities. Therein bromocriptine mesilate is allowed to react with bromothymol blue at pH 2.5. The resulting ion pair is then extracted with benzene and its concentration determined at 410 nm (25). ... 

Now let us consider the results of an E-jump study (14) of proton transfer between picric acid (A) and methyl red (B)... 

The interaction of phenylbiguanide and ethyl p-ethoxypropionate in the presence of sodium methoxide yields a readily dissociable molecular complex of the expected guanamine and phenylbiguanide 486) (CLXIX). Aqueous picric acid cleaves the complex into the picrates of its constituents. However, the complex is not formed from the pre-formed 2- -ethoxyethyl-6-phenylguanamine (or its methyl analogue) and phenyl-biguanide in methanol or acetonitrile, and its nature is not completely understood (see also ref. 605). 

The LFP studies of the reaction of the A-methyl-A-4-biphenylylnitrenium ion with a series of arenes showed that no detectable intermediate formed in these reactions. The rate constants of these reactions correlated neither with the oxidation potentials of the traps (as would be expected were the initial step electron transfer) nor with the basicity of these traps (a proxy for their susceptibility toward direct formation of the sigma complex). Instead, a good correlation of these rate constants was found with the ability of the traps to form n complexes with picric acid (Fig. 13.68). On this basis, it was concluded the initial step in these reactions was the rapid formation of a ti complex (140) between the nitrenium ion (138) and the arene (139). This was followed by a-complex formation and tautomerization to give adducts, or a relatively slow homolytic dissociation to give (ultimately) the parent amine. 

Werner [10] suggested that, on heating, urea tautomerizes to the pseudourea structure which, on reaction with methyl sulfate, allows the isolation of 2-methylpseudourea (Eq. 22). The product was difficult to crystallize and it was isolated as the picric acid derivative. 

Di-m-tolyl methyl tellurium iodide,3 (C7H7)2(CH3)TeI, is obtained in quantitative yield from its components. It crystallises in four-sided columns, soluble in chloroform, insoluble in ether. It melts at 121° to 122° C.s splitting up again into its components. When boiled with water and silver oxide and the solution treated with picric acid, a picrate is formed this separates from alcohol with five molecules of solvent of crystallisation, and melts at 114° to 115° C. The platinichloride melts with decomposition at 154° to 155° C. 

Tri-p-tolyl tellurium iodide1 melts with decomposition at 232° to 233° C., dissolves readily in methyl alcohol or chloroform, less readily in benzene or ether, and is insoluble in water. Tri-p-tolyl tellurium bromide occurs when the iodide or chloride is boiled with silver bromide. It melts at 265° to 266° C. with decomposition, and dissolves in alcohols or chloroform, but is insoluble in benzene or ether. Tri-p-tolyl tellurium chloride is prepared from the bromide in the usual way. It melts at 260° to 261° C. and gives precipitates with the chlorides of mercury, tin and gold, picric acid and platinic chloride. The hydroxide is a resin, melting at about 110° C., and yielding a pier ate, consisting of long prisms, M.pt. 194° to 195° C.a... 

This last induction is confirmed by observations on nitro-mannite, a crystalline solid which appears by reason of this circumstance better suited than liquid methyl nitrate for transmitting detonation. It has in fact given practically constant velocities of 7700 meters per second in lead tubes of 1.9 mm. internal diameter at a density of loading of 1.9. Likewise picric acid, also crystalline, 6500 meters per second.. . . ... 

Indolizidine has been made in 68% yield by the action of silver ions on JV-chloroazacyclononane in dioxane.231 Pyrrolizidine and quinolizi-dine have been prepared similarly but in much poorer yields. Also, 1-methyl-5-hydroxyazacyclononane gave a trans-iustd quaternary salt (172) when heated with either perchloric, hydriodic, or picric acid in ethanol.232 However, it is more usual to apply this reaction in the reverse direction for synthesis of medium ring compounds. 

Tetryl 2,4,6-trinitro- anisole Picric Acid N-methyl-2,4,6- trinitroaniline... 

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