Dinitrogen methylation

Ph.CH2.OMe, Ph.(CH2)2.0Me, Ph.(CH2)3.0Me (2-3, 3-4, 1-3), does not decrease steadily, but goes through a maximum. These two circumstances point to a specific -interaction in nitrations of the ethers with acetyl nitrate which is important with benzyl methyl ether, more important with methyl phenethyl ether, and not important with methyl phenpropyl ether. This interaction is the reaction with dinitrogen pentoxide already mentioned, and the variation in its importance is thought to be due to the different sizes of the rings formed in the transition states from the different ethers. 

From these results it appears that the 5-position of thiazole is two to three more reactive than the 4-position, that methylation in the 2-position enhances the rate of nitration by a factor of 15 in the 5-position and of 8 in the 4-position, that this last factor is 10 and 14 for 2-Et and 2-t-Bu groups, respectively. Asato (374) and Dou (375) arrived at the same figure for the orientation of the nitration of 2-methyl and 2-propylthiazole Asato used nitronium fluoroborate and the dinitrogen tetroxide-boron trifluoride complex at room temperature, and Dou used sulfonitric acid at 70°C (Table T54). About the same proportion of 4-and 5-isomers was obtained in the nitration of 2-methoxythiazole by Friedmann (376). Recently, Katritzky et al. (377) presented the first kinetic studies of electrophilic substitution in thiazoles the nitration of thiazoles and thiazolones (Table 1-55). The reaction was followed spec-trophotometrically and performed at different acidities by varying the... 

This last comment is a warning on the potential risk that dinitrogen tetroxide presents as a reagent vis- i-vis the particular alcohol-acid. The paragraph on hydrocarbons confirms this. This oxide has even caused accidents with saturated hydrocarbons (these can be due to impurities). In any case, there is every chance that oxide will activate the methyl groups of this compound. 

Within this context carbon monoxide is not the inert molecule so frequently depicted on the basis of its formal triple bond and the remarkable similarity of its physical properties to those of the isoelectronic molecule dinitrogen. (Indeed, if it were, atmospheric carbon monoxide would present no hazard ) It is, in fact, a fairly readily activated molecule the industrial process for the production of methyl formate (1) is well known, but it is less widely appreciated that this process is an example of a homogeneous, selective, base-catalyzed, activation of carbon monoxide which has for its net chemistry... 

Methyl methacrylate 4-Methylnitrobenzene 2- Methylpyridine Methylsodium Molybdenum trioxide Naphthalene 2-Naphthol Air, benzoyl peroxide Sulfuric acid, tetranitromethane Hydrogen peroxide, iron(II) sulfate, sulfuric acid 4-Chloronitrobenzene Chlorine trifluoride, interhalogens, metals Chromium trioxide, dinitrogen pentaoxide Antipyrine, camphor, phenol, iron(III) salts, menthol, oxidizing materials, permanganates, urethane... 

Thioanisole, oxidation, by dinitrogen tetroxide, 46,80 by hydrogen peroxide, 46, 80 by lead tetraacetate, 46, 80 reaction with sodium metaperiodate to form methyl phenyl sulfoxide, 46,78... 

The survey of hazards and safety procedures involved in handling rocket fuels and oxidisers includes liquid hydrogen, pentaborane, fluorine, chlorine trifluoride, ozone, dinitrogen tetraoxide, hydrazine, methyl hydrazine and 1,1-dimethyl hydrazine [1]. The later volume [2] is a bargain compendium of five NFPA publications ... 

Azatricyclo[2.2.1.02 6]hept-7-yl perchlorate, 2368 f Azetidine, 1255 Benzvalene, 2289 Bicyclo[2.1.0]pent-2-ene, 1856 2-/ert-Butyl-3-phenyloxaziridine, 3406 3 -Chloro-1,3 -diphenyleyclopropene, 3679 l-Chloro-2,3-di(2-thienyl)cyclopropenium perchlorate, 3388 Cyanocyclopropane, 1463 f Cyclopropane, 1197 f Cyclopropyl methyl ether, 1608 2,3 5,6-Dibenzobicyclo[3.3.0]hexane, 3633 3,5 -Dibromo-7-bromomethy lene-7,7a-dihy dro-1,1 -dimethyl-1H-azirino[l,2-a]indole, 3474 2.2 -Di-tert-butyl-3.3 -bioxaziridinc, 3359 Dicyclopropyldiazomethane, 2824 l,4-Dihydrodicyclopropa[ >, g]naphthalene, 3452 iV-Dimethylethyl-3,3-dinitroazetidine, 2848 Dinitrogen pentaoxide, Strained ring heterocycles, 4748 f 1,2-Epoxybutane, 1609 f Ethyl cyclopropanecarboxylate, 2437 2,2 -(l,2-Ethylenebis)3-phenyloxaziridine, 3707 f Methylcyclopropane, 1581 f Methyl cyclopropanecarboxylate, 1917 f Oxetane, 1222... 

Reaction of methyl bicyck>[1.1 O]butane-l-carboxylate with dinitrogen tetroxidc gave methyl 1,3-dinitrocyclobutane-l-carboxylate (18a) as a mixture of the cis- and frans-isomers in only 17% yield. Similarly, the reaction of dinitrogen tetroxide with the corresponding ethyl ester gave the corresponding isomeric ethyl ester 18b in only 40% yield.33... 

Under a dinitrogen atmosphere, a 300-mL, two-necked, round-bottomed flask containing a magnetic stir bar and fitted with a pressure-equalizing dropping funnel and an inert gas inlet is charged with a solution of 2-aminopropane (10.6 g, 0.180 mol) in dry diethyl ether (70 mL). The flask and its contents are cooled in a dry ice—isopropanol bath to — 78°C then a solution of l-bromo-3-methyl-2-butanone (10.0 g, 0.0606 mol)1 in diethyl ether (20 mL) is added dropwise from the dropping funnel to the stirred solution of amine over 15 min. 

Methyl phenyl sulfoxide has also been prepared from thio-anisole by the action of hydrogen peroxide,2,3 lead tetraacetate,4 and dinitrogen tetroxide,5,6 and from methanesulfinyl chloride and benzene with anhydrous aluminum chloride.7... 

A kinetic study of structural effects on the A-nitrosation of amino acids by nitrite in aqueous solution has established that the dominant term in the rate equation corresponds to nitrosation by dinitrogen trioxide.189 Nitrosation by intramolecular migration of the nitroso group from an initially nitrosated carboxylate group can compete when the transition state has a five- or six-membered ring structure. Nitrosation of A-methyl-4-tolylsulfonylguanidine involves rapid nitrosation of the N-... 

Bis[diazo(trimethylsilyl)methyl] phosphines 239 loose only one equivalent of dinitrogen on warming and are transformed into l,2,4(k3)-diazaphospholes 240139 (equation 81). It is obvious to explain this cyclization by intramolecular ketazine formation of a diazocarbene intermediate, but in light of the preceding discussion, speculations about the bond state of this phosphinocarbene (phosphavinyl ylide or phosphaacetylene) are allowed. 

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