3,5-Dimethyl methyl benzoate

The following liquids may be used (boiling points are given in parentheses) — chlorobenzene (132-3°) bromobenzene (155°) p cymene (176°) o-dichloro-benzene (180°) aniline (184°) methyl benzoate (200°) teti-alin (207°) ethyl benzoate (212°) 1 2 4-trichlorobenzene (213°) iaopropyl benzoate (218°) methyl salicylate (223°) n-propyl benzoate (231°) diethyleneglycol (244°) n-butyl benzoate (250°) diphenyl (255°) diphenyl ether (259°) dimethyl phth ate (282°) diethyl phthalate (296°) diphenylamine (302°) benzophenone (305)° benzyl benzoate (316°). 

A number of researchers have also used a proposed ASTM test mixture, benzaldehyde, acetophenone, methyl benzoate, dimethyl terphtha-late, benzyl alcohol, and benzene to demonstrate separation on a column [98]. However the first four compounds are from the same interaction group and should behave in the same way on changing conditions. The first three have almost constant indices (respectively 760, 800, and 890) so that in effect they create an index scale with constant differences against which the last two compounds can be compared [96,99]. 

Nevertheless the results quoted above for the breakdown of dimethyl hemiorthobenzoate indicate that (kinetic) general acid catalysis should be detectable in the methanolysis of methyl benzoate (Bransted a = 0.49) and probably in the analogous hydrolysis of methyl benzoate. Therefore any mechanism proposed for these reactions must be able to account for this. 

The Hammett p-value for cleavage of the exocyclic bond of 2-methoxy-2-substituted-phenyl-l,3-dioxolans (—1.58 + 0.06) is a little larger than that for cleavage of the endocyclic C— bond of 2-hydroxy-2-substituted-phenyl-l,3-dioxolans (—1.24 + 0.04) (Table 9) (Chiang et al., 1983). A direct comparison between the p-values for C—OMe bond cleavage of trimethyl orthobenzoates and dimethyl hemiorthobenzoates is not possible at present since they have not been measured in the same solvent. However, that based on H+ for the breakdown of the hemiorthobenzoates (— 1.58) is less than that based on the equilibrium constants for their conversion into methyl benzoates and methanol which is —1.9 (derived from the equilibrium constants for formation of the hemiorthobenzoates, McClelland and Patel, 1981b). This implies that the development of positive charge in the transition state is less than in the final product, the ester. 

Fig. 5.1. A sample of floral scent compounds. (1) Substituted methyl esters of benzoic acid. The ester smells unpleasantly sweet when R = H (methyl benzoate), of wintergreen when R = OH (methyl salicylate), and of concord grape when R = NH2 (methyl anthranylate). Odorants with unusual origins and biological functions include the homoterpene 4,8-dimethyl-1,3,7-nonatriene (2) and the wet-earth compound geosmin (3). Some ubiquitous fragrance compounds are ben-zaldehyde (4), benzyl alcohol (5), indole (6), (S)-linalool (7), ( )-/ -ocimene (8), and of-farnesene (9).

C2H,N, Pyridine, 3,5-dimethyl-palladium complex, 26 210 CbHsNO, Benzoyl isocyanide chromium com-C HbO, Ethanone, 1-phenyl-manganese complex, 26 156-158 CBH, 02, Methyl benzoate chromium complex, 26 32 C H i, o-Xylylene magnesium complex, 26 147 ChH P, Phosphine, dimethylphenyl-iron complex, 26 61 ruthenium complex, 26 273 ChH12, 1,5-Cyclooctadiene iridium complex, 26 122 ruthenium complexes, 26 69-72, 253-256 ChH OjPS, 2-Butenedioic acid, 2-(dimethylphosphinothioyl)-dimethyl ester, manganese complex, 26 163... 

OiCsHm, Propanoic acid, 2,2-dimethyl-tungsten complex, 26 223 02C Hh, Methyl benzoate chromium complex, 26 32 02CuiH (, 2,3-Naphthalenediol in prepn. of cu-tetraamminedihaloruthe-nium(III) complexes, 26 66, 67... 

Uranium(VI) fluoride in l,l,2-trichloro-l,2,2-trifluoroethane at 0°C oxidizes12 aldehydes to acid fluorides in moderate yields (e.g., heptanoyl fluoride from heptaldehyde in 47% yield, benzoyl fluoride from benzaldehyde in 40% yield) benzaldehyde gives methyl benzoate and benzaldehyde dimethyl acetal when the reaction mixture is worked up by quenching with methanol.13... 

Methyl benzoate, [93-58-3], CTfCOOCI Ig, bp, 198—200°C at 101.3 kPa d [ , 1.094 n], 1.5205. Insoluble in water, this is a colorless, transparent liquid solidifying at about 15°C. Methyl benzoate is prepared by the direct esterification of benzoic acid and methanol. It is used in the fragrance industry and in the production of other benzoate esters (via transesterification). A technical-grade methyl benzoate is available as a by-product in the manufacture of dimethyl terephthalate [120-61 -6]. 

Treatment of 2-(2-methylphenyl)-5,5-dimethyl-l,4,5,6-tetrahydropyrimi-dine (279) with butyllithium in the presence of /V,/V,Al, /V -tetramethyleth-ylenediamine (TMEDA) in tetrahydrofuran at 0°C under nitrogen, then with methyl benzoates at -50°C gave 6-aryl-6-hydroxy-3,4,6,7-tetrahydro-2//-pyrimido[2,l-a]isoquinolines (280), which gave 6-ary 1-3,4-di hydro-2//-pyrimido[2,l-a]isoquinolines (281) with heating in toluene in the presence of p-toluenesulfonic acid (93JMC3098). 

Flowery Anisyl alcohol Benzyl acetate, phenylaceiate Cinnamic acid Cinnamyl acetate Citronellyl formate Crcsyl acetate Decanal Dimethyl benzyl carbinol Dimethyl benzyl carbinyl acetate Ethyl anthranilate Geranyl acetate Hydroxycitronellal dimethyl acetate Linalool Linalyl acetate Methyl benzoate Pcnethyl acetate 2-Phcnylpropionaldehyde 3-Phenylpropionaldehvde. 

FVP of (5-methyl-2-thiophene-yl)methyl benzoate at 650 °C and 10 Tort pressure has provided 2,5-dimethyl-ene-2,5-dihydrothiophene (S-monomer) in 75% yield via a double [3,3]-sigmatropic shift (Scheme 38). A solution of this compound in a mixture of CHCI3 and CS2 was relatively stable at —78°C. The stmcture was confirmed by... 

Transesterification of methyl benzoate and dimethyl terephthalate with ethylene glycol Na/Na0H/y-Al203 and Cs,0/y-Al203 [38]... 

The photochemical reactions of arenecarboxylic acid esters with alkenes has received recent attention by Cantrell. - For example, irradiation of 2,3-dimethyl-2-butene and methyl benzoate gave a mixture of alkoxyoxetane (56), carbonyl-alkene metathesis product (57) and ketone (58), resulting from alkoxy radical allylic hydrogen abstraction and radical recombination. Such alkoxyoxetane photoproducts are... 

Voltammetric data for ester reductions are available for several aromatic esters [51-54], and in particular cyclic voltammetry shows clearly that in the absence of proton donors reversible formation of anion radical occurs [51]. In dimethylfonnamide (DMF) solution the peak potential for reduction of methyl benzoate is —2.29 V (versus SCE) for comparison dimethyl terephthalate reduces at —1.68 V and phthalic anhydride at —1.25 V [4]. Half-wave potentials for reduction of aromatic carboxylate esters in an unbuffered solution of pH 7.2 are linearly correlated with cr values [51] electron-withdrawing substituents in the ring or alkoxy group shift Ei/o toward less negative potentials. Generally, esters seem to be more easily reducible than the parent carboxylic acids. Anion radicals of methyl, ethyl, and isopropyl benzoate have been detected by electron paramagnetic resonance (epr) spectroscopy upon cathodic reduction of these esters in acetonitrile-tetrapro-pylammonium perchlorate [52]. The anion radicals of several anhydrides, including phthalic anhydride, have similarly been studied [55]. 

Acylation of Mes2BCHzLi (2) with methyl benzoate for 5 min gave a 72% yield of acetophenone, marginally better than for use of benzoyl cMoride or benzoic anhydride. However, acylation of other dimesitylboryl-stabilized anions does not appear to be of general use, often giving only modest yields. The ethoxycarbonylation shown in equation (38) leads to ethyl octanoate in 50% yield. When dimethyl carbonate was used, a-methylation occurred in preference to ester homologation. ... 

CIC The powerful odour is dominated by 2-isobutyl thiazole and 3-pentanethiol. The green notes are lipid degradation products like (E)-2-hexenal, hexanal and higher unsaturated aldehydes, the pineapple-pear like fruity notes are derived from methyl hexanoate, ethyl-2-hexenoate and hexyl acetate. The spicy cinnamon notes are represented by 3-phenyl propyl acetate, cinnamyl acetate, methyl cinnamate, ethyl cinna-mate and ciimamaldehyde. Gamma-decalactone and 2,5-dimethyl-4-hydroxy-furan-3(2H)-one and 3-hydroxy-2-butanone add the sweet, creamy body. Beta-famesene, citronellol, 2-phenylethanol, beta-ionone add the sweet, floral, quincelike part and methyl benzoate and ethyl benzoate impart a characteristic medicinal, exotic topnote. 

Under the same basic conditions /ra . -l-acetoxymethyl-1-methyl-2-tosylcyclopropane generated an a-sulfonyl anion, which attacked the ester group intramolecularly and afforded 2,5-dimethyl-l-tosyl-3-oxabicyclo[3.1.0]hexan-2-ol (22) in 50% yield.Stereoselective synthesis with a chiral cyclopropyl sulfoxide was experienced when ( )-4-tolylsulfinylcyclopropane was reacted first with butyllithium and then with methyl benzoate and gave 1-benzoyl-1-[(5)-4-tolylsulfinyl]cyclopropane (23a) in 62% yield. A useful reaction took place when 2-(hy-droxymethyl)cyclopropyl phenyl sulfide was treated first with an excess of butyllithium and then with dimethylformamide and gave 2-hydroxy-l-phenylsulfanyl-3-oxabicyclo[3.1.0]hexane (24), a lactol which has been used to carry out various useful synthetic transformations. Another useful reaction occurred when cyclopropyl phenyl sulfones were treated with butyllithium followed by an acyl imidazole to give acyl cyclopropanes in decent yield. 

Methyl- and 2,3-dimethylquinoxalines have been acylated with benzoate, trifluoroacetate, oxalate, and phthalate esters using sodium hydride as the condensing agent. Both mono- and diacyl derivatives are obtained from 2,3-dimethylquinoxaline with excess of methyl benzoate and diethyl oxalate the products 55 and 56 are obtained, respectively. Compound 57 is produced by condensation of the dimethyl compound with diethyl phthalate. ... 

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