Methyl benzoate procedure

Madclung synthesis, 27-30 Mannich alkylation, 106, 119 7-mcthoxyindole, procedure for, 8 6-methoxyindole-3-carboxaldehyde, procedure for, 115 116 methyl 4-[5-(benzyloxycarbonyl)indol-3-yl]methyl-3-methoxy-benzoate, procedure for, 108... 

This procedure appears to be fairly general for the aroylation of /3-diketones to give 1,3,5-triketones. Using this method, the submitters2 have aroylated benzoylacetone with methyl benzoate (87%), methyl />-chlorobenzoate (78%), and ethyl nicotinate (69%). Also, acetylacetone has been monobenzoylated with methyl benzoate to form l-phenyl-l,3,5-hexanetrione in 75% yield or dibenzoylated with the same ester to form 1,7-diphenyl-... 

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). 

Problem 20.12 When benzoic acid is eslerified by methanol in the presence of a little sulfuric acid, the final reaction mixture contains five substances benzoic acid, methanol, water, methyl benzoate, sulfuric acid. Outline a procedure for the separation of the pure ester. 

Addition of ethyl A-benzylideneglycinate to tetraethyl ethenylidenediphosphonate in EtONa/EtOH medium produces tetraethyl 3-amino-3-(ethoxycarbonyl)-l,l-propylidenediphospho-nate in excellent yield after deprotection (95%, Scheme 8.62). A complementary procedure uses DBU in THF. Under these conditions, the reaction of methyl benzoate with tetraethyl ethenylidenediphosphonate proceeds well at 50°C to give tetraethyl 3-phenyl-3-(ethoxycarbonyl)-l,l-propylidenediphosphonate. °... 

Pyridine has also been used as the basic catalyst and chloride acceptor for benzoylation reactions. In one procedure, amines, volatile alcohols or thiols isolated by benzene extraction, are benzoylated with pyridine (1 ml) and benzoyl chloride (0.5 ml) by shaking intermittently at room temperature for several hours. The pyridine phase is extracted with 2 M HCl and the excess benzoyl chloride is hydrolysed with water for 12 hours. After shaking with 2 M sodium carbonate to remove benzoic acid, the benzene solution is dried and concentrated for analysis [144]. Aminoglycoside antibiotics are derivatized to the benzoyl derivatives in a similar reaction using 90 fi of pyridine and 10 /il of benzoyl chloride at 80 °C for 30 minutes. The pyridine is evaporated in a stream of nitrogen and excess benzoyl chloride is converted to methyl benzoate with methanol, again at 80°C, for 10 minutes. The product is cleaned up for analysis by a rather involved solvent extraction procedure [145]. 

Design and execute an experimental procedure for separating benzyl alcohol (7) from methyl benzoate (8) by normal-phase column chromatography. 

A ( )-Enol-l 1-acetates are formed by distillation of acetic anhydride in the presence of / -toluenesulphonic acid. Another procedure employed for the synthesis of enol benzoates involves treatment with benzoic anhydride and triphenyl methyl sodium or ethynyl sodium. Suitable procedures utilizing a diluent have been developed for the enol esterification of a 20-ketone without affecting an 11-ketone. 

It should be mentioned that the Food Additives Analytical Manual (FAAM) [75] provides analysts with FDA evaluated methodology (partly subjected to collaborative study) needed to determine compliance with food additive regulations, including procedures for indirect food additives, such as butylated hydroxy-anisole (BHA), butylated hydroxytoluene (BHT), t-butylhydroxyquinone (TBHQ), dilaurylthiopropionate (DLTDP), fatty acid methyl esters (FAME), sodium benzoate, sorbitol, and others. 

Condensation of 2,4-dihydroxypropiophenone (172) with benzoyl chloride and sodium benzoate goes to afford chromone 174, probably via ester 173. This procedure is known as the Kostanecki-Robinson reaction Methylation (175) of the remaining phenolic function by means of dimethyl sulfate, followed by reaction... 

This procedure is used in pharmacopoeial assays of benzyl benzoate, dimethyl phthalate, ethyl oleate, methyl salicylate, cetostearyl alcohol, emulsifying wax, castor oil, arachis oil, cod liver oil, coconut oil. 

Variations of the above procedures are sometimes employed. /S-Keto esters may be obtained by alcoholysis of the intermediate diacyl esters by sodium methoxide in methanol, as in the preparation of methyl /3-oxocaprylate (88%). The starting /S-keto ester can be converted to the new /S-keto ester in a single step. Thus, in the synthesis of ethyl ben- > zoylacetate (55%)> ethyl acetoacetate and ethyl benzoate are converted directly to this keto ester by distilling the lower-boiling product, ethyl acetate, thereby forcing the reaction to completion. ... 

Pans-2-Iodocyclohexyl acetate can be isolated in essentially quantitative yield from the reaction of thallium(I) acetate, iodine, and cyclohexene in a 1 1 1 molar ratio in refluxing chloroform. lodo acetates from a representative series of alkenes including cyclohexene have been similarly prepared in 80-98% yield in glacial acetic acid which was not dried as described in this procedure. The corresponding iodo benzoates are obtained in comparable yields from reaction with thallium(I) benzoate and iodine in benzene. The deactivated olefin methyl cinnamate did not react under these conditions, and o-allylphenol underwent ring iodination to... 

To expedite the synthesis of densely packed dendrons, Percec and co-workers110 have utilized the triply branched monomer 37, methyl 3,4,5-trihydroxy-benzoate.84-85 111-113 The materials were synthesized by coupling the phenolic groups of the monomer to 3 equiv of a benzylic chloride, followed by transformation of the focal ester functionality to a chloromethyl group, via LiAlFF reduction and SOCT chlorination. This procedure could be repeated up to the fourth generation. 

Similar procedures apply to the alkylation of esters and for the carbonation and carboethoxylation of esters and ketones. In a synthesis of a-amyrin from gly-cyrrhetic acid, Corey and Cantrall effected clean methylation of the 20-ketone-3-benzoate (1) to the 19/3-methyl derivative (2) by treating a solution of (1) in dioxane... 

This reaction type differs from die three-component reaction reported by Grigg et al. Thus, Grigg et al. [53] (Scheme 7) immobihzed 3-iodo-4-(N-acetyl-N-(2-methyl-2-propenyl)amino)benzoate (36) onto a sohd support. In the presence of suitable Pd salts, Pd substituted the iodide function of the aromatic. The proximal isopropyhdene group trapped the resulting metalated species in an intramolecular Heck reaction. The resulting alkyl palladium species (37) could then react with a suitable carbanion equivalent. The authors used vinylstaimanes or boronates for this purpose, which they obtained in situ from alkynes by hydroboration or hydro-starmylation. The latter procedure allowed them to attach the same vinylic species via its terminal carbon (boronate) (41) and its subterminal carbon (stannane) (39). 

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