IV-phenylcarbamates

IV-Phenylcarbamic acid, see Propham 3-Phenylcatechol, see o-Phenvlphenol lV-Phenyl-3-chlorocarbamic acid, see Chlorpropham... 

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

An optimized inexpensive synthesis of tetrahydrothiopyran 4-one which lends itself to scale-up involves a Dieckmann cyclization of dimethyl 3,3 -thiobispropanoate <2007S1584>. Efficient conversions to 3,6-dihydro 4-trimethylsilyloxy-27/-thiopyran <2007S1584>, the corresponding 4-vinylstannane <2007JOC1507> and the 4-oxo-tetrahydro-27/-thiopyran-3-yl A-methyl-iV-phenylcarbamate <2007SL293> have been accomplished. 

The Hill reaction has served as a target for structure-activity studies with phenylureas, iV-phenylcarbamates, polycyclic ureas, acylanilides, s-triazines, uracils, dihalogenated benzoni-... 

Ethyl IV-phenylcarbamate was transesterified by methanol in the presence of DBU to afford methyl Al-phenylcarbamate in 18% conversion (85EUP152240). 

Considering the large difference between the fcB values of compounds I and II, the base catalyzed transformation of 4-nitrophenyl-iV-phenylcarbamate (II) must proceed by a different reaction mechanism. In this case, the first step of tho reaction is an elimination that is similar to the -elimination discussed earlier (see Eq. 10) ... 

Methyl iV-phenylcarbamate has been reacted with formaldehyde to give a biscarbamate that was pyrolyzed to 4,4 -diisocyanatodiphenylmethane. Can a catalyst be... 

Ethyl IV-phenylcarbamate, 4,4 -methylenebis(ethyl phenylcarbamate), 4,4 -methylenebis(phenyl isocyanate) and 10 decomposition products were separated as their urea derivatives on a C g column (A = 254 nm) using a 75/25 acetonitrile/ water (1% TEA to pH 3.0 with H3PO4) mobile phase [973]. Very good resolution and peak shapes were obtained. Elution was complete in 30 min and detection limits were reported to be 1-7 ng injected (analyte dependent). 

In the case of 3,4-dimethyknetalloles 58, which are stable in their monomeric form (see Section III.A.l), the method proposed was the thermolysis of iV-phenylcarbamates 57, the decomposition of which is regioselective (equation 22). Intracyclic C—H elimination giving the metallole 58 is the main process (80-90%), and the transoid isomer 59 is always the minor product. Tertiary Af-phenylcarbamates 57 decompose at about 70 C in common solvents. In carbon tetrachloride, one can follow easily toe progress of toe reaction by NMR spectroscopy. An interesting one-pot synthesis is possible with two equivalents of phenyl isocyanate, the side products are gaseous carbon dioxide and diphenylurea which precipitates (equation 23) " . ... 

The IV-phenylcarbamates (86), derived from 2-acetamido-2-deoxy-gluconohydroximino-lactone, and its chitobiono-lactone equivalent were synthesized as potential inhibitors of N-acetylglucosaminidases. ... 

Heating the ethoxy-diazoline (661) with ethyl propiolate yields not only the fission products p-nitrobenzonitrile and ethyl iV-phenylcarbamate, but also ethyl p-nitrobenzoate and the pyrazole (662) the last two products arise from the rearranged 1,3-dipolar compound (663). ... 

Figure 37 Enantiodivergent oxidation of geranyl iV-phenylcarbamate by A. niger.

Figure 39 Preparation of diastereomeiic diols from citronellyl iV-phenylcarbamate.

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