Diphenyl carbamate

CH3NH-CO-NHCH3 (dimethyl urea) + (C6H50)2C0 (diphenyl carbamate) CH3NCO + byproducts... 

This urethane forms white crystals, melting at 61° C., which on heating to 200° to 250° C. decompose forming phosgene and diphenyl carbamic chloride. Cold water decomposes it into diphenylamine, hydrochloric acid and carbon dioxide. 

Strikovsky AG, Kasper D, Grun M, Green BS, Hradil J, Wulff G (2000) Catalytic molecularly imprinted polymers using conventional bulk polymerization or suspension polymerization Selective hydrolysis of diphenyl carbonate and diphenyl carbamate. J Am Chem Soc 122 6295... 

Diphenyl phosphate N,N -diethyl(4-vinylphenyl)amidine MMA EDMA MeCN, cyclohexanol+dodecanol or toluene Using transition state analog selective hydrolysis of diphenyl carbonate and diphenyl carbamate bulk and suspension polymerization [174)... 

Chelating ion exchangers of functional dithizone (diphenyl carbamate) groups are widely applied in concentration, separation and recovery of noble metal ions [44-54]. 

Fig. 9.14. (a) Mass spectrum of the unknown TP of diclofenac, (b) Mass spectrum of closest NIST match, diphenyl carbamic chloride. Source [283]. 

To avoid the issne of product inhibition, Wnlff etal. investigated the hydrolysis of carbonates and carbamates, which release prodncts with no significant affinity for the amidine active site. Rate enhancements for the hydrolysis of diphenyl carbonate and diphenyl carbamate were fonnd to be 588 and 1435, respectively, compared to the nncatalyzed reaction. ... 

Similarly, nitroben2ene, carbon monoxide, and methanol can react sequentially in the presence of noble metal catalysts, to produce methyl A/-phenylcarbamate [2603-10-3] (4). The phenylcarbamate is subsequently coupled with formaldehyde [50-00-0] to yield the methylenebis(carbamate) (5) which is pyroly2ed to yield methylene diphenyl diisocyanate (MDI) (23). 

V-Hydroxypfperidinyl Carbamate 47. 4,5-Diphenyl-3-oxazolin-2-one 4 xBenzyl Carbamate... 

Rhodamine B vaseline [155] diphenyl, polyphenols [156] maleic and fu-maric acids [162] flavonoids [158] alcohols as 3,5-dinitrobenzoates [159, 160] gangliosides [161] 1-hydroxychlorden [162] carbamate pestiddes [163] para-thion and its metabolites [164] polyethylene and polypropylene glycols [165] terpene derivatives [166] menthol [167]... 

Many methods have been proposed and are used to study the thermal stability of propellants and to ensure the absence of possible autocatalysed decompositions during storage. None are sufficiently reliable to merit individual description. In practice, stabilisers are added, the usual being diphenylamine for nitrocellulose powders and symmetrical diethyl diphenyl urea (carbamate or centralite) for double base propellants. Provided a reasonable proportion of stabiliser remains, the propellant can be assumed to be free from the possibility of autocatalytic decomposition. The best test of stability is therefore a chemical determination of the stabiliser present. 

Preparation of diphenyl l-(benzylcarbamoyl)-4-(phthalimido)-l-phosphonate — Reaction of a phthalimido-protected aminoaldehyde with a triaryl phosphite in the presence of benzyl carbamate... 

A flange flask was loaded with 1,6-hexanediol (50.37 g 0.43 mol), dihydroxyethyl hexamethylene bis-carbamate (15.23 g, 0.05 mol) and diphenyl ether (50 % equal weight) and was heated to 80 °C until a solution was obtained. 

The photochemistry of aryl carbonates and aryl carbamates is interesting, as these compounds are building blocks of polycarbonates and polyurethanes. Diphenyl carbonate (165) has been irradiated with ultraviolet (UV) light [122,123] and... 

Crich and Rumthao reported a new synthesis of carbazomycin B using a benzeneselenol-catalyzed, stannane-mediated addition of an aryl radical to the functionalized iodocarbamate 835, followed by cyclization and dehydrogenative aromatization (622). The iodocarbamate 835 required for the key radical reaction was obtained from the nitrophenol 784 (609) (see Scheme 5.85). lodination of 784, followed by acetylation, afforded 3,4-dimethyl-6-iodo-2-methoxy-5-nitrophenyl acetate 834. Reduction of 834 with iron and ferric chloride in acetic acid, followed by reaction with methyl chloroformate, led to the iodocarbamate 835. Reaction of 835 and diphenyl diselenide in refluxing benzene with tributyltin hydride and azobisisobutyronitrile (AIBN) gave the adduct 836 in 40% yield, along with 8% of the recovered substrate and 12% of the deiodinated carbamate 837. Treatment of 836 with phenylselenenyl bromide in dichloromethane afforded the phenylselenenyltetrahydrocarbazole 838. Oxidative... 

The nature of the aromatic substituents is apparently not critical for SSRI activity, as indicated by the structure of duloxetine (23-5), where one ring is replaced by thiophene and the other by naphthalene. The synthesis starts as above by the formation of the Mannich base (23-1) from 1-acetyl thiophene with formaldehyde and dimethyl-amine. Treatment of that intermediate with the complex from lithium aluminum hydride and the 2R,3S entantiomer of dimethylamino-l,2-diphenyl-3-methyl-butane-2-ol gives the S isomer (23-2) in high enantiomeric excess. Treatment of the aUcoxide from (23-2) and sodium hydride with 1-fluoronaphthalene leads to the displacement of halogen and thus the formation of ether (23-2). The surplus methyl group is then removed by yet another variant of the von Braun reaction that avoids the use of a base for saponifying the intermediate urethane. Thus, reaction of (23-3) with trichloroethyl formate leads to the A -demethylated chlorinated urethane (23-4). Treatment of that intermediate with zinc leads to a loss of the carbamate and the formation of the free secondary amine duloxetine (23-5) [23]. 

Ethylenedioxybutyl)-3-trichloro-acetamido 1 cyclohexene, 58, 9, 11 Ethylene, 1,1-diphenyl-, 56, 32 Ethylene glycol, 56, 44 Ethylene glycol, phenyl-, 55, 116 Ethylene, tetramethyl-, 56, 35 Ethyl-or-fluoro-l-naphthaleneacetate, 57, 73 Ethyl 2-fluoropropanoate, 57, 73 3-Ethylhexane, 58, 3, 4 3-ETHYL-1-HEXYNE, 58,1, 2, 3, 4 Ethyl levuhnates, 5-substituted, 58, 81 Fthyl nitrite, 58, 113, 115 Ethyl V-nitroso-A-fp-tolylsulfonylmethyl)-carbamate, 57, 96 3-Ethyl-3-pentanol, 58, 25, 26, 31 3-Ethyl-3-pentyl alcohol, 58, 78 3-Ethyl-3-pentyl fluoride, 58, 78 Ethyl A -(p-tolylsulfonylmethyl)carbamate, 57, 95... 

The condensation of methyl N—phenyl carbamate witli IICHO to methylene diphenyl diurethane has been studied in a batch reactor in the presence of cation exchanged resins. Unlike conventional H0SO4 catalyst, fresh resin catalysts did not form a byproduct N—benzyl compound. However, accumulation of water from repeated uses of the catalyst caused a decreased activity and the formation of the byproduct. The deactivated catalyst could be completely regenerated by drying in vacuo. Ethylacetate and toluene were found to be efficient solvents with the resin catalysts. 

Processes are under development to manufacture methylene diphenyl diisocyanate (MDI) without using toxic and corrosive phosgene. The proposed process schemes usually consist of three steps alkoxycarbonylation of nitrobenzene or aniline with CO and an alcohol to alkyl plienylcarbamate, condensation of the carbamate, and then thermal decomposition of the resulting urethane to MDI. For example, the condensation of methyl N—phcnylcarbamate (MPC), and IICHO into methylene diphenyl diurethane (MDU) is carried out in the presence of an acid catalyst. 

---