Phenylcarbamate

Carbamates are produced by the oxidative carbonylation of amines in alcohol, and active research on the commercial production of carbamates as a precursor of isoyanates based on this reaction has been carried out. As an example, ethyl phenylcarbamate (582) is produced in a high yield (95%) with... 

Phenylcarbamates. Phenylcarbamate herbicides represent one of two subgroups of carbamate herbicides, the phenylcarbamates and the thiocarbamates (299). Both groups are prone to volatilization losses the thiocarbamates are particularly susceptible and should be sod-incorporated immediately after apphcation (2). The carbamate herbicides are used, in general, for the selective pre-emergence control of grass and broadleaved weeds (299). Exceptions would include barban, desmedipham, and phenmedipham which are appHed post-emergence. 

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). 

A Wild and Woolly Photolabile Fluorescent Ester, 195 A/-Phenylcarbamate, 195 Borate, 196... 

Mixed cellulose 10-undecenoate/U is(3,5-dimethyl-phenylcarbamate) bonded on silica gel [59,71] [51]... 

We have investigated Ce(IV) ion-carbamates, such as methyl and butyl 4-methylphenyl-carbamate, (MTC and BTC, respectively), or methyl, ethyl, and butyl phenylcarbamate, (MFC, EPC and BPC, respectively), systems for AAM polymerization [19]. It was found that the presence of carbamate compounds can promote the polymerization and enhance the rate of AAM polymerization (Rp) in descending order as ... 

The structural effect of alkyl groups such as methyl, ethyl, and -butyl on the Rp is small. Alkyl 4-methyl-phenylcarbamate can be chosen as a model compound for the hard segment of poly(ether-urethane) (PEU). This group can initiate grafting reaction with Ce(IV) ion and the grafting site was proposed at the hard segment of PEU [3,15] as shown in Scheme (1). 

Although the initial radical formed from the reaction of Ce(rV) ion and acetylanilide (AA) and N-p-tolylacet-amide (PTA) has never been observed in the ESR studies, the presence of AA, PTA moieties in the end group of PAN obtained from initiating the CAN-AA, CAN-PTA system have been detected by the FT-IR spectra analysis method. Similar results were observed in the end group analysis of CAN-phenylcarbamate, CAN-N-acyl-N -tolylurea initiation systems. 

Reaction of methyl a-L-rhamnopyranoside with triphenylboroxole gave a syrupy boronate ester which was characterized as a crystalline phenyl-carbamate. Removal of the phenylboronic acid residue gave a product identified as methyl a-L-rhamnopyranoside 4-N-phenylcarbamate, since it was identical with that resulting from removal of the ketal group from methyl 2,3-O-isopr opylidene-a-L-rhamnopyranoside 4-N-phenylcarbamate (12). This establishes the structure of the original ester as methyl a-L-rhamnopyranoside 2,3-phenylboronate (24). 

In acid solution 1-acyl-1//-azepines and alkyl l//-azepine-l-carboxylates undergo rapid aromatization to A-arylcarbamates,115,139,142 whereas 1/Z-azepine-l-carbonitrile suffers quantitative rearrangement and hydrolysis to phenylurea.163 Rearrangement of ethyl l//-azepine-l-carboxylate to ethyl A-phenylcarbamate is also rapid (5 min) and quantitative with boron trifluoride-diethyl ether complex in benzene.245... 

The N-phenylcarbamic acid methyl ester was purchased from TCI America. 

Figure 3. Proposed chemical reactions leading to stabilization of phenylamide, phenylcarbamate and phenylurea pesticides In soils. (From ACS Symposium Series No. 29, 1976) (173).

Chiralcel OC Cellulose tris(phenylcarbamate) coated on silica gel [19] Daicel... 

Chiracel OD CXi-Acid glycoprotein oq-Acid glycoprotein Amylose tris (3,5-dimethyoxy-phenylcarbamate)... 

---