Methyl benzenecarboxylate

It is likely that the benzenecarboxylic acids are derived from lignin units where the a-carbon of the side-chain has been oxidized to a carboxyl group (52), and different studies have interpreted the structures and distributions of the methyl esters of benzenecarboxylic acids as indicating that these structural units exist as either free or ester-bound structures in the HA 10,16,17,24)- However, it has recently become clear that certain benzenecarboxylic acids are produced from unoxidized lignin moieties by the TM AH reagent in the course of the reaction at elevated temperatures 41), Examination of the products from the TMAH thermochemolysis of a model lignin dimer, free of any carboxylic functionality, showed the production of relatively large amounts of methylated benzenecarboxylic acid derivatives. These authors... 

METHYL BENZENECARBOXYLATE (93-58-3) Combustible liquid (flash point 181 °F/83°C). Incompatible with strong acids, nitrates, oxidizers. 

A13-00525 Benzoic acid, methyl ester CCRIS 5851 Clorius EINECS 202-259-7 Essence of niobe FEMA No, 2683 HSDB 5283 Methyl benzenecarboxylate Methyl benzoate Methylester kyseliny benzoove Niobe oil NSC 9394 Oil of niobe UN2938. Used in perfumery, as a solvent for cellulose esters and ethers, resins, rubber flavoring. Liquid mp = -15° bp = 199° d = 1.0933 insoluble in H2O, soluble in organic solvents Xm = 228,272,280 nm (s = 11000, 830, 686, MeOH) LDso (rat orl) n 1177 mg/kg. Lancaster Synthesis Co. Morflex Penta Mfg. Pentagon Chems. Ltd Sybron. 

Synonyms benzoic acid methyl ester methyl benzenecarboxylate Niobe oil... 

Scheme 9.140. A representation of the process of ester interchange. The methoxy group of methyl benzenecarboxylate (methyl benzoate) is replaced by an ethyoxy group from ethanol (ethyl alcohol, CH3CH20H).The reaction is depicted as the acid-catalyzed substitution of an ethoxy for a methoxy.

In contrast, the second item in Table 9.9 involves acid rather than base. Here, as shown in Scheme 9.140, the oxygen of the carbonyl group of methyl benzenecarboxylate (methyl benzoate) is protonated, the tetrahedral intermediate is generated. 

In 1931 Ing pointed out that formula (II) and (III) do not contain methyl or potential methyl groups in j ositions 6 and 8 which they occupy in cytisoline. Further, a partially reduced quinoline ought to oxidise easily to a benzenecarboxylic acid and so far the only simple oxidation, products recorded from cytisine were ammonia, oxalic acid and isovaleric acid. Distillation of cytisine with zinc dust or soda-lime yields pyrrole and pyridine, but no quinoline. On these grounds Ing suggested that cytisine should be formulated without a quinoline nucleus, and that the reactions which indicate the presence of an aromatic nucleus in the alkaloid can be accounted for by an a-pyridone ring. This a-pyridone nucleus can... 

Different phenolic derivatives with lignin-related structures were also released. Among them, we note the presence of some benzenecarboxylic acids, some of them being lignin structures with p-hydroxycoumaryl, guaiacyl and syringyl skeletons, peaks (1) 4-methoxybenzenecarboxylic acid methyl ester, (4) 3,4-dimethoxybenzenecarboxylic acid methyl ester, (7) 3,4,5-... 

The aromatic acids released from different HA upon pyrolysis in the presence of TMAH probably represent original components of the HA structure released by the thermolytic action of TMAH (10,12,16,17). This observation is supported by the TMAH thermochemolysis data of Hatcher et al. (23) and Hatcher and Clifford (16) for a volcanic soil humic acid. In fact, the C-NMR spectrum of this particular HA (shown in Figure 4) clearly indicates that it is composed of only aromatic and carboxyl carbons. Conventional pyrolysis of these HA produced trace quantities of volatile products without the release of any significant compounds while pyrolysis in the presence of TMAH yielded mainly benzenecarboxylic acid methyl esters (Figure 5), in accordance with the NMR data. 

In a detailed study on methylated permanganate-degradation products of aquatic humic and fulvic acids (originating from Black Lake, North Carolina, and Lake Drummont, Virginia) by means of gas chromatography/mass spectrometry, Liao et al. (1982) found methyl esters of benzenecarboxylic acids, furancarboxylic acids, aliphatic mono, di, and tribasic acids, and (car-boxyphenyl) glyoxylic acids (Table 3). The degradation products of fulvic and humic fractions from the two lakes were qualitatively similar, but dis-... 

Saiz-Jimenez, C., Pyrolysis/methylation of soil fulvic acids benzenecarboxylic acids revisited. Environ. Sci. TechnoL, 28, 197-200, 1994. 

SYNONYMS avolin, 1,2-benzenedicarboxylic acid, dimethyl-l,2-benzenedicarboxylate, dimethyl ester of 1,2-benzenecarboxylic acid, DMP, methyl phthalate. 

Benzene carboxaldehyde. See Benzaldehyde Benzenecarboximidamide, 4,4 -[1,6-hexanediylbis (oxy) bis-. See Hexamidine Benzenecarboxylic acid. See Benzoic acid Benzene chloramine. See Chloramine-B Benzene chloride. See Chlorobenzene Benzene, 1-chloro-2-isocyanato-. See2-Chlorophenyl isocyanate Benzene, 1-chloro-3-isocyanato-. See3-Chlorophenyl isocyanate Benzene, 1-chloro-4-isocyanato-. See4-Chlorophenyl isocyanate Benzene, 2-chloro-4-isocyanato-1-methyl-. See 3-Chloro-4-methylphenyl isocyanate Benzene, (chloromercuho)-. See Phenylmercuric chloride Benzene, chloromethyl-. See Monochlorotoluene... 

Scheme 9.9. A representation of the pathway for the reaction of methyl phenyl ketone (acetophenone) with sodium hypochlorite (NaOCl) in aqueous base to produce chloroform (CHCI3) and benzenecarboxylic acid (benzoic acid). An example of the halofonn reaction.

Scheme 9.145. A representation of proton removal from the methyl group of ethyl ethanoate (ethyl acetate, CH3CO2CH2CH3) generating a resonance-stabilized carbanion. Attack of the latter at the carbonyl of ethyl benzenecarboxylate (ethyl benzoate, C6H5CO2CH2CH3) and ethyl ethanoate (ethyl acetate, CH3CO2CH2CH3) to yield, respectively, ethyl 3-phenyl-3-oxopropanoate and 3-oxobntanoate (ethyl acetoacetate, CH3COCH2CO2CH2CH3). An example of the Claisen condensation.

Enantiomeric (E)-cyclooctene (20E) was first resolved in 1963 through its diastereomeric platinum(II) complex. Synthesis of optically active 20E has been the subject of intensive study since 1968. The first preparation involves the treatment of enantiopure (E)-cyclooctane-l,2-thiocarbonate with triisooctyl phosphate or of (E)-cyclooatane-l,2-trithiocarbonate with l,3-dibenzyl-2-methyl-l,3,2-diazaphospholi-dine. Following analogous synthetic routes, enantiomeric (E)-cycloheptene (18E) can be produced and trapped by 2,5-diphenyl-3,4-isobenzofuran as an optically active adduct. In 1973, the circular dichroism spectrum of enantiopure 20E vapor was recorded in the vacuum UV region down to 150 nm. The first enantiodifferentiating Z-E photoisomerization of cyclooctene sensitized by chiral benzenecarboxylates appeared in 1978. Transfer of chiral information from sensitizer to substrate occurs within the exciplex intermediate. ... 

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