Methoxy-methyl-carbamic

Pcntacarbonyl[(methoxy)(methyl)carbene]chromium(0) (16, R1 = R2 = Me 475 mg, 1.9 mmol) and the chiral ene carbamate (see above equation) (718 mg, 3.8 mmol) in CH2Ci2 (20 mL) were placed in a Fischer Porter pressure tube and saturated with CO (3 eycles to 6.33 atm of CO) and then irradiated (450-W Conrad-Hanovia 7825 medium-pressure lamp, Pyrex well) under 6.33 atm CO overnight. The yellow-green solution was filtered through a pad of Cclitc, and the solvent evaporated. The crude mixture was placed in a sublimation apparatus and heated at 30-50°C (1 Torr) until no further Cr(CO)6 could be obtained. The residue was preabsorbed on silica gel and flash chromatographed yield 319 mg (61 %) mp 133-134"C. 

In general, benzimidazole-2-methyl carbamate derivatives (28) can be synthesized by the reaction of an appropriate diamine (26) with 1,3-dicarbo-methoxy-5-methylisothiourea (27) [43], This is the most general and economic synthesis for benzimidazole carbamates. However, the same reaction was less than satisfactory when the aza analogues of o-phenylenediamines (29) were used. In order to synthesize the aza analogues of mebendazole (2) or flubendazole (3), the reactions of methoxycarbonyl isothiocyanate (30) with a wide variety of diamines such as 3,4-diaminopyridines, 4,5-diaminopyrimi-dines, o-phenylenediamines have been investigated in the presence of dicyclo-hexylcarbodiimide [44, 45] and were found to be quite successful in the synthesis of carbamates (31). 

AZIRIN0(2, 3 3.1t)PYRROLO(l,2-a)INDOLE- l,7-DIONE, 6-AMINO-1, la,2,8,8a,8b-HEXAHYDRO-8-(HYDROXYMETHYL)-8a-METHOXY-5-METHYL-,CARBAMATE (ester)... 

The introduction of a carbonyl carbamate group at position 4 of the pyrazol-3-one ring can be done directly by fusion of appropriately 2-substituted /i-keto ester with a hydrazine (04TJC659) (Scheme 16). The jS-keto ester 67 was synthesized in two steps from ethyl 4,5-dioxo-2-phenyl-4,5-dihydrofuran-3-carboxylate 65 by decarbonylation to ethoxy-carbonylbenzoylketene intermediate 66 in refluxing benzene and then nucleophilic addition by methyl carbamate. Ethyl 2-benzoyl-3-[(methoxy-carbonyl)amino]-3-oxopropanoate 67 with diphenylhydrazine on heating in benzene gave 4-substituted pyrazol-3-one 68 in 44% yield. 

This same methoxy—methyl combination reaction was used as a reference in deriving the absolute kinetic parameters of the reactions of methoxy with methyl formate [192], methyl acetate [367] and dimethyl carbamate [368] (Table 33). 

Reaction of 2 methoxy 4"propenyl phenyl methyl carbamate, 11, with... 

Reaction of 2-methoxy-4-propenyl phenyl methyl carbamate, 11, with 4-pheny1-1,2,4-triazoline-3,5-dione, 1. A 100 ml round-bottomed flask was charged with 1.58 g (9.04 x 10 mole) of I and 40 ml of CH2CI2. The red solution was cooled in an ice bath with stirring. To this red solution, a... 

Copolymerization Reaction of 2-Methoxy-4-propenyl Phenyl Methyl Carbamate,... 

Simple" ester enolates (those derived from mono-esters) can be used to prepare amino acids. The lithium enolate of t-butyl acetate reacted with the methoxy group in 1.185, for example, to give the methyl carbamate of /-butyl 3-aminobutanoate. 

CN [3-[[2-methoxy-4-[[[(2-methylphenyl)sulfonyl]amino]carbonyl]phenyl]methyl]-l-methyl-lH-indol-5-yl]carbamic acid cyclopentyl ester... 

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... 

Thus, we anticipate the initial products are 3,4-dichloroaniline and N-methyl, N-methoxy-carbamic acid. 

Dichlorobis(diisopropoxy)titanium(IV). Titanium(IV) chloride. Zinc iodide. DIELS-ALDER REACTIONS 2-Acetoxy-I-methoxy-3-trimethylsilyloxy-1,3-butadiene. 4-Acetoxy-1 -trimethylsilyl-1,3-butadiene. Benzyl irans-l,3-butadiene-l-carbamate. 1,3-Bis(/-butyldimethylsilyloxy)-2-aza-1,3-diene. 2,3-Bis(trimethylsilyl)methyl-1.3-buladiene (10-1,3-Dimethoxybutadiene 4-I)iniethyhnnino 1,1,2... 

Eight methyl AT-(l/f-benzimidazol-2-yl)carbamates 78 with various 5-substituents have been labelled with 13C at carbon-2, and at the carbonyl and methoxy carbons according to the synthetic scheme of equation 25 using commercially available 13C-enriched (91-92 atom%) carbon tetrachloride, methanol and thiourea63. The three labelled positions indicated with asterisks are at or near the site involved in binding to tubulin (which performs a variety of vital functions in the cell). A correlation has been found between anthelmintic potency of the benzimidazole carbamate group of anthelmintic drugs widely used to control nematode parasites in sheep and their ability to bind tubulin. 

BENZOYL-lH-BENZIMIDAZOL-2-YL)-CARBAMIC ACID METHYL ESTER see MHLOOO p-BENZOYLBENZOIC ACID see BDL860 a-BENZOYLBENZYL CYANIDE see OOK200 BENZOYL CHLORIDE see BDM500 BENZOYL CHLORIDE (DOT) see BDM500 BENZOYL CHLORIDE, METHOXY-(9CI) see AOY250 BENZOYL CYANIDE-o-... 

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