Methyl benzoate preparation

A solution of 18.7g (0.079 mole) of methyl benzoate, prepared above, in 200 ml of anhydrous ether was added dropwise to a slurry of 3.8g (0.10 mole) of L1A1H4 in 20 ml of ether. After addition was completed, the reaction mixture was continued to stir for half an hour before being qu iched by aqueous NaOH solution. The solution was filtered and washed with saturated NaHCOj and water. After solvent is removed, the solid was recrystallized from hexane/ether mixture to give a white crystalline product (12.1g, 68%). NMR spectra confirmed the structure of product. 

The preparation of a number of miscellaneous acids is described. m-Nitrobenzoic acid. Although m-nitrobenzoic acid is the main product of the direct nitration of benzoic acid with potassium nitrate and concentrated sulphuric acid, the complete separation of the small quantity of the attendant para isomer is a laborious process. It is preferable to nitrate methyl benzoate and hydrolyse the resulting methyl w-nitrobenzoate, which is easily obtained in a pure condition ... 

A cleai-cut answer was provided by Irving Roberts and Harold C. Urey of Columbia University in 1938. They prepared methanol that had been enriched in the rnass-18 isotope of oxygen. When this sfflnple of methanol was esterified with benzoic acid, the methyl benzoate product contained all the label that was originally present in the methanol. 

Ethyl Benzoate.—This ester has not been found, so far, to occur naturally in essential oils. It has, however, been prepared by synthetic processes, for example, by condensing ethyl alcohol with benzoic acid by means of dry hydrochloric acid gas. Its odour is very similar to that of methyl benzoate (q.v.), but not quite so strong. It is an oil of specific gravity I OfilO, refractive index 1 5055, and boiling-point 213° at 745 mm. It is soluble in two volumes of 70 per cent, alcohol. 

This method was later adapted for the large-scale preparation of the LTD4 antagonist 64 by another Merck Process Research group (Figure 3.11) [21], Conversion of a methyl benzoate to the corresponding acetophenone was required. Formation of the tertiary alcohol was again minimized with the addition of H M DS and excellent reaction performance was achieved. 

Following are the percentage yields obtained in the preparation of other esters ethyl maleate, 73 ethyl salicylate, 70 ethyl oxalate, 80 ethyl benzoate, 92 methyl benzoate, 87. In the preparation of ethyl maleate troublesome emulsions were encountered in working up the product. Occasionally this hap-... 

An appropriately functionalized isoquinoline (38) bearing a benzyl group is prepared from an aromatic aldehyde (37). The benzyl position is metalated with LDA and the resulting carbanion is reacted with a highly substituted methyl benzoate to produce a ketone (39). The isoquinoline nitrogen is alkylated with ethyl a-bromoacetate and the resulting quaternary salt is cyclized... 

Methyl m-nitrobenzoate has been prepared by the esterification of m-nitrobenzoic acid 1 this method is, however, obviously much less satisfactory than nitration of methyl benzoate. Nitration by means of fuming nitric acid has also been applied to methyl benzoate,2 but the use of the ordinary nitration mixture of concentrated sulfuric add and concentrated nitric acid is more satisfactory. 

R = CH2C6Hs, C14H12O2, Mr 212.25, 6p2.okPa 170-171 °C, df 1.1121, ng 1.5680, is the main component of Peru balsam oil. It occurs in fairly large amounts in a number of blossom concretes and absolutes (e.g., tuberose and hyacinth). It forms either a viscous liquid or solid flakes mp 21 22°C) and has a weak, sweet-balsamic odor. It is prepared either by transesterification of technical methyl benzoate with benzyl alcohol, or from benzyl chloride and sodium benzoate. A third process starts with benzaldehyde which is converted in high yield into benzyl benzoate in the presence of sodium or aluminum benzylate (Tishchenko reaction). 

A urethane latex composition, (I), was prepared by Kent et al. (1) and used as an in situ delivery agent for 4-hydroxyl-methyl benzoate, which was useful as an image stabilizer. Polyurea, (II), and polyurethane latex compositions were also prepared by the authors (2) containing pendant acid groups as latex stabilizers and as crosslinking sites. 

Methyl benzoate, anisole, and diphenyl ether each give sandwich compounds with chromium vapor, although in rather low yield (32, 55, 110). Chromium appears to attack alkyl ethers and this deoxygenation probably competes with complexation with the aromatic oxygen compounds. No simple product has been isolated from chromium atoms and aniline, but bis(7V,7V-dimethylaniline)chromium has been prepared (32). The behavior of molybdenum and tungsten vapors closely resembles that of chromium in reactions with oxygen- and nitrogen-substituted arenes (113). 

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]. 

Cyclization of 2-[(3-acetamido-2-pyridyl)amino]benzoic acid (202) in 0.5 N sulfuric acid gave 6-amino-ll//-pyrido[2,l-h]quinazolin-ll-one (203) (84MI3). 2-[(6-Methyl-, 5-nitro-, and 3-nitro-2-pyridyl)amino]benzoic acids were cyclized into 9-methyl, 8-nitro, and 6-nitro-l 1 //-pyrido[2,l -ujquina-zolin-ll-ones, respectively, by the action of 80% sulfuric acid. Ethyl 2-(2-pyridylamino)benzoate, prepared in the reaction of 2-chloropyridine and ethyl anthranilate in boiling toluene for 10 h, afforded ll//-pyrido[2,l-b]-quinazolin-ll-one (27) on heating at 200-210°C for 0.5 h (92MI2). 

The Grignard reagent—magnesium phenyl bromide—is prepared as described in Preparation 21 from 1-2 gms. (1 mol.) of dry magnesium and 8 gms. (1 mol.) of dry bromobenzene. 6-8 gms. (1 mol.) of dry methyl benzoate dissolved in 25 gms. of sodium-dried ether are added to the cold solution, slowly and with constant shaking. The liquid is then heated on a water bath until no further change takes place. Ice and dilute sulphuric acid are added to the cold reaction mixture, which, when the precipitate has dissolved, is steam distilled. The triphenyl carbinol which remains is recrystallised from benzene. 

The above compound can also be made using 10 gms. of cone, sulphuric acid, 100 gms. of absolute alcohol, and 50 gms. of benzoic acid. Although less alcohol is used, the yield is 90% theoretical, being increased by the dehydrating action of the sulphuric acid. Methyl benzoate (B.P. 199°) can be prepared in a similar manner. 

Preparation 212.—Methyl Benzoate (Methyl ester of benzenemono-carboxylic acid). 

Diazomethane was prepared by the method of Moore and Reed,3 using 10% extra 2-(2-ethoxyethoxy)ethanol and an extra 100 ml. of water over that recommended to prevent stirring difficulties in the later stages of the distillation. The ethereal diazomethane solution was dried at 0° over KOH pellets, and the concentration was determined by reaction of an aliquot with henzoic acid and determining the resulting methyl benzoate by vapor phase chromatography. 

The deuterium content can be determined by reaction of the deuterated diazomethane with benzoic acid-O d in anhydrous ether followed by analysis of methyl benzoate for deuterium content either by n.m.r. spectrometry or by mass spectrometry. The benzoic acid-O-d is prepared by heating a mixture of 48.6 g. (0.216 mole) of benzoic anhydride (obtained from Aldrich Chemical Company, Inc.), 0.10 g. (0.0009 mole) of anhydrous sodium carbonate, and 7.0 g. (0.35 mole) of deuterium oxide to 90° for 2 hours. The resulting mixture is distilled at atmospheric pressure in a short-path still fitted with a receiver protected from atmospheric moisture by a drying tube. After removal of a forerun, b.p. 100-101°, the benzoic... 

The optically pure albuterol may be prepared by resolving a mixture of enantiomers methyl benzoate albuterol precursors which prepared by procedures well known to persons skilled in the art. The starting material 4-benzyl albuterol is commercially available from Cipla (Bombay, India). 

It is not possible to prepare biaryls containing a free carboxyl group directly by the diazo reaction. No biaryl is formed when (a) diazotized aniline and sodium benzoate, (b) diazotized anthranilic acid and aqueous sodium benzoate, or (c) diazotized anthranilic acid and benzene are used as components in the reaction.13 On the other hand, the reaction proceeds normally if methyl benzoate is used in reaction (a) or when methyl anthranilate replaces the anthranilic acid in (b) and in (c). The success of the diazohydroxide reaction appears to lie in the ability of the non-aqueous liquid to extract the reactive diazo compound from the aqueous layer.4 However, esters and nitriles can be prepared from esters of aromatic amino acids and cyanoanilines and also by coupling with esters of aromatic acids, and from the products the acids can be obtained by hydrolysis. By coupling N-nitrosoacetanilide with ethyl phthalate, ethyl 4-phenylphthalate (VIII) is formed in 37% yield. 

Calibration Standards Prepare four HQ calibration standards as follows Add 0.50, 1.00, 2.00, and 3.00 mL of HQ Stock Solution into separate 10-mL volumetric flasks, then add 2.00 mL of Methyl Benzoate Stock Solution (internal standard) to each, dilute to volume with pyridine, and mix. In the same manner, prepare four DTBHQ Stock Solution calibration standards. Prepare the trimethylsilyl derivative of each standard as follows Add 9 drops of calibration standard to a 2-mL serum vial, cap the vial, evacuate with a 50-mL gas syringe, add 250 p,L of A.O-bistrimethylsilylacetamide, and heat at about 80° for 10 min. 

Sample Preparation Transfer about 1 g of sample, accurately weighed, into a 10-mL volumetric flask, add 2.00 mL of Methyl Benzoate Stock Solution, dilute to volume with pyridine, and mix. Prepare a trimethylsilyl derivative as described under Calibration Standards (above). 

Mobile Phase Prepare a 60 40 mixture of Solution A and Solution B, filter, and degas. Make adjustments to the Mobile Phase, if necessary, to obtain baseline separation of thiamine hydrochloride and methyl benzoate. 

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