Methylbenzoate, reaction

This was dissolved in 550 ml of absolute benzene and the so-formed solution added to a mixture of 248 ml of absolute methanol and 550 ml of absolute benzene. After the exothermic reaction had terminated, the reaction mixture was boiled for a further 20 hours, then concentrated in vacuo and the product, 4-methylbenzoic acid methyl ester, isolated by conventional means. It could be purified by distillation, and the purified product boiled at 91°C/9 mm Hg, MP 32°C. 

Predict the product of the reaction of p-methylbenzoic acid with each of the following ... 

Similar treatment of an arenediazonium salt with CuCN yields the nitrile, ArCN, which can then be further converted into other functional groups such as carboxyl, for example, Sandmeyer reaction of o-methylbenzenediazonium bisulfate with CuCN yields o-methylbenzonitrile, which can be hydrolyzed to give o-methylbenzoic acid. This product can t be prepared from o-xvlene by the usual side-chain oxidation route because both methyl groups would be oxidized. 

B. Ethyl l-Amino-S-methylbenzoate. A 1-1., three-nocked, round-bottomed flask equipped with a mechanical stirrer, a condenser, and a nitrogen-inlet tube is charged with 11.25 g. (0.050 mole) of ethyl 4-amino-3-(methylthiomethyl)benzoate, 300 ml. of absolute ethanol, and 17 teaspoons (ca. 50 g.) of W-2 Raney nickel (Note 7). The reaction mixture is stirred at 25° for one hour, then stirring is discontinued, and the ethanolic solution is decanted from the catalyst (Note 8). The catalyst is then washed with one 300-ml. portion of absolute ethanol and one 500-ml. portion of dichloromethane, the solvent being removed... 

Photochemical oxygen transfer reactions involving sulfoxides have also been documented. For example, a photochemical rearrangement of 2-nitrophenyl phenyl sulfoxide to 2-nitrosophenyl phenyl sulfone224, and the inverse photoconversion of o-methylbenzoic acid225 have been reported. Finally, photochemical epimerizations of the sulfoxide centers... 

Carboxylic acids such as acetic acid react with alcohols such as methanol or with methoxytrimethylsilane 13 a in the presence of trimethylchlorosilane (TCS) 14 in THF or 2-methyl-THF to give esters such as methyl acetate in 97% yield and hex-amethyldisiloxane 7. Even methyl pivalate can be readily prepared in 91% yield [111]. Reaction of a variety of carboxylic acids, for example N-benzoylglycine 329, with two equivalents of yS-trimethylsilylethanol 330 and with 14 has been shown to afford esters such as 331 in 98% yield [112, 112 a]. Likewise, silylated carboxylic acids react with silylated alcohols or thiophenols in the presence of 4-trifluoro-methylbenzoic anhydride and TiCl4/AgCl04 to furnish esters or thioesters in high yields [113, 114] (Scheme 4.43). 

Methylphenol is carboxylated to 2-methyl-4-hydroxybenzoate by a methanogenic-enrich-ment culture before degradation to acetate (Figure 8.44a) (Roberts et al. 1990) C-labeled bicarbonate prodnced carboxyl-labeled acetate, while C-methyl-labeled 3-methylphenol yielded methyl-labeled acetate. However, 2-methylbenzoate formed by dehydroxylation of 2-methyl-4-hydroxybenzoate was not further metabolized (Figure 8.44b). A similar reaction occnrs with a sulfate-reducing mixed culture (Ramanand and Suflita 1991). 

Nitropyrido[l,2-A]quinolin-6-ium-l 1-olate (6%) was isolated from a reaction mixture obtained by photoirradiation of crystalline photochromic 2-(2, 4 -dinitrobenzyl)pyridine for 10 days <2004JP0865>. Reaction of l-(3-chloropropyl)-6,7-dimethoxy-3-methylbenzo[c]pyrylium perchlorate with hydrazines and hydroxylamine in refluxing MeOH afforded 9,10-dimethoxy-6-methyl-, -4,6-dimethyl-l,2,3,4-tetrahydropyridazino[6,l-tf]isoquinoli-nium, and 9,10-dimethoxy-6-methyl-l,2,3,4-tetrahydro[l,2]oxazino[3,2- ]isoquinolinium, perchlorates, respectively <2004CHE1131>. 

It is required to determine the height (h) of a bubble-column reactor and the outlet partial pressure of oxygen (A, pAout) for the hquid-phase oxidation of o-xylene to o-methylbenzoic acid the column diameter (D) is 1 m. The reaction is... 

These authors also reported that /V-acyloxy-/V-alkoxyamides did not undergo methanolysis under the same conditions but treatment of /V-acctoxy-/V-ethoxybenz-amide 25a in more forcing conditions with NaOMe in DME afforded a mixture of ethyl and methylbenzoate, 97 and 98 (Scheme 20). They attributed the formation of the former to a HERON reaction and methyl benzoate to the direct attack of methoxide at the amide carbonyl. 

The reesterification model reaction kinetics of methylbenzoate by heptanole-1 in catalyst (TBT) presence and without it was studied at 443 K on the gas chromatograph Biokhrom using diphenyloxide according to the earlier described method [5] as an internal standard. The rate constant k was calculated according to the equation of irreversible reaction of the first order. 

The kinetics of reesterification model reaction of methylbenzoate by heptanole-1 in mica presence was studied at 443 K. Mica catalytic activity was determined on the observed rate constant of the first order k at the twentieth multiple of heptanole-1 excess and mica contents 30 mass.% in calculation on the methylbenzoate [2],... 

The rate of the base-catalysed condensation of carbonyl compounds with alkyl groups activated by Jt-deficient aromatic systems is enhanced by the addition of quaternary ammonium salts. For example, 2-methylbenzoxazole, 2-methylbenzo-thiazole and 4-nitrotoluene react with a range of substituted benzaldehydes to produce the corresponding 2-styryl derivatives (62-80%) at room temperature over 1 -2 hours [61, 62]. The intermediate alcohol can also be isolated after a short reaction time. 

The product of the reaction between bis(S-aminodithionitrito)nickel(ii), NH3, HCHO, and MeOH has the structure (179). Complexes of 2,1,3-benzothiadiazole, 2,1,3-benzoselenadiazole, isothiazole, 2-methylbenzo-... 

Methylbenzoic acid 513 can be laterally lithiated with two equivalents of lithium amide base (LDA" or L1TMP °) or alkyllithium provided the temperature is kept low to avoid addition to the carbonyl group (Scheme 201). It is usually preferable to carry out the lithiation using aUcyllithiums", since with lithium amides the subsequent reaction of 514 with electrophiles is disrupted by the presence of the amine by-product (diisopropylamine, for example) . The dilithio species 514 is stable in THF even at room temperature, and (as with the amide 483) since LDA will also dilithiate 515 stabilization presumably comes principally from conjugation with the carboxylate. 

In the middle of the 1950s, Knott reported the synthesis of dyesmffs based on benzothiazole derivatives. Alkylation of Al-methylbenzo-l,3-thiazole-2-thione with a-bromoacetophenone and deprotonation of the resulting thiocarbonylium salt 5 yielded, after spontaneous desulfurization of the intermediate thiirane (7), the alkylidene derivative 8 (18) (Scheme 5.1). In order to rationalize the reaction, thiocarbonyl ylide 6 was proposed as the precursor of thiirane 7. To the best of our... 

This does not occur in the case of catalyst and reactants here described. With Bronsted-type catalysis, the reaction between the benzoyl cation, Ph-C" =0, and the hydroxy group in phenol is quicker than the electrophilic substitution in the ring. This hypothesis has been also confirmed by running the reaction between anisole and benzoic acid in this case the prevailing products were (4-methoxy)phenylmethanone (the product of para-C-benzoylation) and methylbenzoate (obtained by esterification between anisole and benzoic acid, with the co-production of phenol), with minor amounts of phenylbenzoate, phenol, 2-methylphenol and 4-methylphenol. Therefore, when the 0 atom is not available for the esterification due to the presence of the substituent, the direct C-acylation becomes the more favored reaction. 

Iodo-7-methylbenzo[l,2-/ 4,3- ]dithiophene 65 undergoes nucleophilic substitution on reaction with copper cyanide in DMF to produce the nitrile derivative 66 (Equation 10) <1997TL457>. 

Benzofuran-3(2/f)-ones (396) exist in the keto form but undergo ready enolization. Acetylation with acetic anhydride and sodium acetate affords 3-acetoxybenzo[6]furans, but reaction under acidic conditions usually supplies these products admixed with 3-acetoxy-2-acetylbenzo[6]furans. Alkylation usually furnishes a mixture of O- and C-alkylated products. 3-Acetoxy-6-methoxy-4-methylbenzo[6]furan, on Vilsmeier reaction, supplies the 3-chlorobenzo[6]furan-2-carbaldehyde, the product expected from an enolizable ketone (72AJC545). Benzofuran-3(2//)-ones react normally with carbonyl reagents. Grignard reagents react in the expected way and dehydration of the intermediate affords a 3-substituted benzo[6]furan. The methylene group is reactive so that self condensation, condensation with aldehydes and ketones and reaction with Michael acceptors all occur readily. 

Treatment of the photooxide of 9-phenylanthracene (445) with aqueous acid results in the formation of 3-(o-hydroxyphenyl)-1 -phenylbenzo[c ]furan (446). Replacement of the 9-phenyl group of anthracene by methyl results in the formation of the more unstable 3 -(o-hydroxyphenyl)-1 -methylbenzo[c]furan. A mechanism for this reaction has been proposed (Scheme 115) (74BSF2521). 

The first example of a [2 + 4] cycloaddition of a thiophene 1-oxide seems to be the formation of a 1 1 mixture of the syn and anti isomers of 3-(2,4,6-trimethylphenyl)-8b-methylbenzo[6]thieno[2,3-mesitonitrile oxide with 3-methyIbenzo[6]thiophene 1-oxide (Scheme 190) (79TL4845). The cycloaddition seems to be regioselective. 

There are several examples of this approach to thiophenes. The reaction of thiophenol with acetylene in the vapor phase at 600-650 °C gave benzo[h]thiophene in 71% yield. p-Toluenethiol affords 5-methylbenzo[h ]thiophene in 54% yield under the same conditions (54HC(7)l). The best example of this type of synthesis was the reaction of 3-mercaptocy-clohexanones (235) with glyoxal to form the thiophenes (236), which was the subject of a patent (70USP3511854). The reaction proceeds smoothly under reflux conditions, using ah inert solvent, such as benzene or toluene, which will azeotrope with water, and a protic acid catalyst. A solution of (235) in the solvent is added to 40% aqueous glyoxal solution containing some acid. After reflux the thiophene (236) can be isolated in 70-90% yield. 

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