Urea 3-methyl-1,1-diphenyl

Stabilizer Carbamite (diphenyl diethyl urea), methyl centralite (diphenyl dimethyl urea), chalk and diphenylamine Increase shelf life of propellant... 

Quinoxaline 1-oxide (209) reacts with phenyl isocyanate to give 2-anilinoquinoxaline (210) together with 1,3-diphenyl-l-(2-quinoxalinyl)-urea (211) and cyclized oxidation product of the urea 212.215 2-Quinoxalinone 4-oxide (205) and its 1-methyl derivative undergo addition reactions, e.g., with phenyl isocyanate and benzyne to give compounds 214 and 216, respectively.216 These reactions are formulated as proceeding via the intermediate cycloadducts 213 and 215. Compound 216 has also been obtained by photolysis of 3-(o-hydroxy-phenyl)quinoxaline 1-oxide.51 1,3-Dipolar cycloaddition of quinoxaline... 

IR spectra, 5, 740 methylation, 5, 101 Urea, JV-arylthio-1,2,4-thiadiazoles from, 6, 492-493 Urea, N-(4-ethoxy-6-methylpyrimidin-2-yl)-JV,JV -diphenyl-reactions... 

There are a series of communications about the formation of dihydroazines by direct reaction of urea-like compounds with synthetic precursors of unsaturated carbonyls—ketones, containing an activated methyl or methylene group. The reaction products formed in this case are usually identical to the heterocycles obtained in reactions of the same binuclephiles with a,(3-unsatu-rated ketones. For example, interaction of 2 equiv of acetophenone 103 with urea under acidic catalysis yielded 6-methyl-4,6-diphenyl-2-oxi- 1,6-dihydro-pyrimidine 106 and two products of the self-condensation of acetophenone— dipnone 104 and 1,3,5-triphenylbenzene 105 [100] (Scheme 3.32). When urea was absent from the reaction mixture or substituted with 1,3-dimethylurea, the only isolated product was dipnon 104. In addition, ketone 104 and urea in a multicomponent reaction form the same pyrimidine derivative 106. All these facts suggest mechanism for the heterocyclization shown in Scheme 3.32. 

Stabilizers such as diphenylamine, 2-nitrophenylamine, dinitrotoluene, IV-methyl-p-nitroaniline, centralites, or acardites (e.g., AW-diphenyl -urea), to increase chemical stability by combining with decomposition products. 

In order to produce methyl isocyanate in good safety s conditions, Bayer A.-G. has developed an industrial process based on the reaction of diphenyl carbonate with N,N -dimethyl urea at high temperature according to scheme 158 (Ref. 212). 

Benzoin, tetraphenylethanediol, hydrazobenzene and 1,2-diphenyl-1,2-ethanedione bishydrazone are oxidized by methyl bis(l-naphthyl)bismuthi-nate to benzil, benzophenone, azobenzene and diphenylacetylene, respectively [88CL2021] (Section 5.2.4). Amides, thioamides, ureas and thioureas are A-acylated in good yield with acetic acid in the presence of the bismuthi-nate at room temperature [90CL1651] (Scheme 3.11). 

Syntheses of this type are from urea, thiourea, and amidine and guanidine derivatives. Ureas give tetrahydro-l,3,5-triazin-2-ones on reaction with a primary amine (1 equiv.) and aqueous formaldehyde (2-30 equiv.). In general, alkyl and aryl amines, unsaturated amines, amino alcohols, and a-amino esters form triazinone derivatives (Equation (43)). Methyl and benzyl have proven to be the most useful urea substituents with respect to high yields and product solubility. N,N -Dicyclohexyl- and A,A -diphenyl-urea gave poor yields of triazinone <90TL2109>. 

Dimethyl-1,3-diphenylurea EINECS 210-283-4 Methyl centralite N.N -Dimethyl carbanilide N,N -Dimethylcarbanilide N,N -Dimethyl-N,N -diphenylurea NSC 59781 Urea, N,N -dimethyl-N,N-diphenyl- Zentralit I Zentralit II. Used for explosives. Plates mp = 122 bp = 350 Xm = 243 nm (s = 9270, MeOH) slightly soluble in Et20, CeHe, CS2, very soluble in H2O, EtOH, MezCO, CHCI3. 

X-Ray analy.ses have been performed on salts of diphenyl phosphoric, phenylphosphonic, and trichloromethylphosphonic acids " phosphorylated urea and thiourea derivatives phenyl[[ -acetyloxy(4-nitrophenyl)]methyl]phosphinic acid ... 

Diphenylamine and certain derivatives of urea, N,N -diethyl-N,N -diphenyl urea (cen-tralite I) and N -methyl-N,N -diphenyl urea (acardite II) are used as stabilizers in propellant. 

Methyl centralite (Centralite II) N,N -dimethyI-N,N -diphenyl -urea... 

Scheme 2.23 Oxidative carbonylation of aniline to synthesize diphenyl urea or A/-phenyl methyl carbamate.

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