Methyl diphenyl isocyanate

The pyrido[l,2-tf][l,3,5]triazine-2,4(3//)-dione derivative 89 was obtained in a cycloaddition reaction of diphenyl-methyl isocyanate 90 with 2-pyridyl isocyanate 91 derived from the corresponding acyl azide via Curtius rearrangement <2002ARK438>. Compound 89 was also synthesized by the reaction of diphenylacetyl chloride 118 and picolinyl azide 116a in the presence of triethylamine (Scheme 11) <2002ARK438>. ... 

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... 

The photolysis of the meso-ionic 1,4-diphenyl-1,2,4-triazol-3-one (200, R1 = R3 = Ph, R2 = H) was stated97 to yield phenyl isocyanate (13%), iV.N -diphenylurea (23%), and the bicyclic compound 215 (49%). These results were interpreted in terms of the fragmentation of the photo-intermediate 213 yielding the JV-phenyldiazirine (214).97 A later publication by the same group97b reports different results. Photolysis of meso-ionic 1,4-diphenyl-1,2,4-triazol-3-one (200, R1 = R3 = Ph, R2 = H) was stated to yield97 phenylisocyanate and the bicyclic compound 215. Later studies,7b have shown that the bicyclic compound 215 is not produced by the photolysis of 200, R1 = R3 = Ph, R2 = H. Irradiation in methanol-methylene chloride gave methyl phenylcar-bamate (25%), benzimidazole (18%), and azobenzene (7%). 

Irradiation of a benzene solution of 5-phenyl Af-benzoylformyl-A-p-tolylthiocar-bamate 48a (Scheme 23) gave 5-phenyl-5-phenylthio-3-p-tolyloxazolidine-2,4-dione 49a in 61% yield accompanied by oxazolidine-2,4-dione dimer (15%), p-tolyl isocyanate (22%), and diphenyl disulfide [29]. Photolysis of 48a in the solid state gave oxazolidine-2,4-dione 49a in 96% yield. For the N-methyl derivative, 48b, compared to the solution photochemistry in which only 8% of oxazolidinedi-one 49b was obtained with a complex mixture, radical cyclization proceeds selectively to give oxazolidinedione in 75% yield in the solid state. Whereas N-p-tolyl and A-methyl derivatives, 48a and 48b, formed achiral crystals, the N-benzyl derivative 48c crystallized in chiral space group P2. Photolysis of the chiral... 

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). 

Amino-5-methyltriazole and carbethoxy isothiocyanate, stirred in acetonitrile, gave 3-methyl-5-thioxo-l,2,3-triazolo[l,5-a][l,3,5]triazin-7-pne (104) (25°C, 30 min, 65%) (76JHC589). 5-Phenyltriazole-4-diazonium chloride and phenyl isocyanate, stirred in dichloromethane, provided 3,6-diphenyl-l,2,3-triazolo[5,l-d][l,2,3,5]tetrazine-4-one (105) (25°C, 41%) (79TL4253). Finally, diazotized 4-aminotriazole was coupled to 2-naphthol. The product, refluxed in methanol, was cyclized to naphtho[2,l-e][l,2,3]-triazolo[l,5-h] triazine (106) (2 days, 80%) (74JHC867). 

CYCLOADDITIONS f-Butyicyanoketene. a-Chloro-N-cyclohexylpropanaldoxime. Chlorosulfonyl isocyanate. Dichloroke-tene. Dimethyl acetylenedicarboxylate. Diphenyl ketene, 2-Methoxyallyl bromide. 2-Methoxy-6-methyl-l,4,3,5-oxathiadia-zine 4,4-dioxide. Oxygen, singlet. 4-Phen-yl-l,2,4-triazoline-3,5-dione. Silver fluoro-borate. Trimethylsilyldiazomethane. 

The l-(hydroxyamino)-2,3-diphenyl- or l-(hydroxyamino)-2-methyl-3-phenylcyclopropen-ylium ion 10 (R = Ph, Me), reacted with two molar equivalents of isocyanates in the presence of triethylamine to give the 1,2,4,6-tetrasubstituted derivatives of 4,6-diazaspiro[2.3]hex-l-en-5-one 12 in moderate to good yield. The reaction presumably proceeds through the formation the -[(aminocarbonyOoxyJcyclopropenimines 11, to which another molecule of the isocyanate subsequently adds. ... 

A non-phosgene process for the production of methyl isocyanate, starting from methylamine and diphenyl carbonate as raw materials, has been established by EniChem/Polimeri Europa, resulting in the commercialization of two production units in the USA (1988) and China (1994) [78]. 

In other applications, Baysal utilized methylene dicyclohexyl isocyanate to link polybutadiene with polystyrene or poly(methyl methacrylate) to form the appropriate block copolymers(70). Diphenyl methane-4,4 diisocyanate was similarly used to prepare a block... 

Methyl-3-morpholino-2-pentenethioic acid anilide treated with phenyl isocyanate, whereupon after generation of heat and liquefaction the mixture is heated ca. 2 hrs. on a steam bath l,3-diphenyl-5-methyl-6-ethyl-4-thiouracil (Y 80%) suspended in a soln. of hydrated Na-acetate in acetic acid, stirred and treated with 36%-H202 below 35° with water cooling, stirring continued for 3 hrs. l,3-diphenyl-5-methyl-6-ethyluracil (Y 80%). F. e. s. G. Bianchetti, P. Dalla Groce, and D. Pocar, G. 94, 606 (1964). 

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