Anhydride benzoic, reaction with alcohols

Bismuth(III) triflate is also a powerful acylation catalyst that catalyzes reactions with acetic anhydride and other less reactive anhydrides such as benzoic and pivalic anhydrides.113 Good results are achieved with tertiary and hindered secondary alcohols, as well as with alcohols containing acid- and base-sensitive functional groups. 

The method described is adapted from the procedures of Kym 3 and Engelhardt, Latschinoff, and Malyscheff.4 Thio-benzoic acid has been prepared by the reaction of benzoyl chloride with potassium sulfide,4 hydrogen sulfide in pyridine,6 6 and magnesium bromide hydrosulfide.7 It is formed from dibenzoyl disulfide with potassium hydrosulfide,4 potassium hydroxide,4 8 and ammonia.9 It is also formed from dibenzoyl sulfide, from phenyl benzoate, and from benzoic anhydride with alcoholic potassium hydrosulfide.4 It has been obtained from dibenzoyl sulfide and hydrogen sulfide,10 carbon oxysulfide and phenyl-magnesium bromide,11 12 dibenzyl disulfide and sodium ethoxide,13 benzyl chloride and sulfur in the presence of potassium hydroxide,14 and benzylthiosulfuric acid and alkali.18 16... 

Blaser and Spencer used aroyl halides in place of aryl halides, with aroyl chlorides being of specific interest as ubiquitous, relatively cheap compounds ( Blaser reaction ) [24], This latter reaction is normally conducted in aromatic solvents phosphines are not used here as catalyst ligands since they fully inhibit the reaction. In the same way, benzoic acid anhydrides can be used as the aryl source in combination with PdCl2 and catalytic amounts of NaBr [79]. In this reaction, one of the arenes is used in the coupling reaction by elimination of CO, whereas the other benzoate serves as the base. The benzoic acid thus formed can easily be recycled into the anhydride. The use of aryl and vinyl triflates according to Cacchi [25] and Stille [26] extends the scope of the Heck coupling to carbonyl compounds phenol derivatives act via triflate functionalization as synthetic equivalents of the aryl halides. The arylation of cyclic alkenes [27], electron-rich vinyl ethers [28], and allylic alcohols [29] is accessible through Heck reactions. Allylic alcohols yield C-C-saturated carbonyl compounds (aldehydes) for mechanistic reasons (y9-H elimination), as exemplified in eq. (6). 

In 1993, Vedejs et al. [5,6] showed that tributylphosphine is a potent catalyst for the acylation of alcohols by acetic and benzoic anhydrides as efficient as 4-(di-methylamino)pyridine DMAP [7,8]. However, the DMAP catalyst is more versatile since it presents catalytic activity in the reaction of alcohols with a larger variety of electrophiles. Due to these properties, Fu [9] realized the design and synthesis of a new family of chiral nucleophilic catalysts illustrated by the planar-chiral DMAP derivative I which is a very efficient catalyst in different enantioselective reactions such as addition of alcohols to ketenes [10], rearrangement of O-acylated azalactones [11], and kinetic resolution of secondary alcohols [12-14]. 

Polymer plasticization can be achieved either through internal or external incorporation of the plasticizer into the polymer. Internal plasticization involves copolymerization of the monomers of the desired polymer and that of the plasticizer so that the plasticizer is an integral part of the polymer chain. In this case, the plasticizer is usually a polymer with a low Tg. The most widely used internal plasticizer monomers are vinyl acetate and vinylidene chloride. External plasticizers are those incorporated into the resin as an external additive. Typical low-molecular-weight external plasticizers for PVC are esters formed from the reaction of acids or acid anhydrides with alcohols. The acids include ortho- and iso-or terephthalic, benzoic, and trimellitic acids, which are cyclic or adipic, azeleic, sebacic, and phosphoric acids, which are linear. The alcohol may be monohydric such as 2-ethylhexanol, butanol, or isononyl alcohol or polyhydric such as ethylene or propylene glycol. The structures of some plasticizers of PVC are shown in Table 9.1. 

As with inorganic solid catalysts, the most extensively studied system was acetic acid—ethanol [428,432,434,444—448]. Other alcohols used in kinetic studies were methanol [430,449,450], 2-propanol [438], 1-bu-tanol [429,431,433,451—458], allyl alcohol [459], 1-pentanol [434] and ethyleneglycol [460] besides acetic acid, the reactions of formic [450], propionic [443,461], salicylic [430,449], benzoic [453—457] and oleic acids [430,451—453] and of phthalic anhydride [462] have been reported. Investigation of a greater variety of reactants is reported in only one paper [463] six alcohols (C4, Cs and C8) and five acids (mainly dicarboxylic were studied. Transesterification kinetic studies were performed with ethyl formate [437,439,441], isobutyrate [437,439—441] acetate [402, 435—437,439—442], methoxyacetate [441] and acrylate [403,404,464, 465] the alcohols used were methanol [402,435,437,439—442,450],... 

Esters have been prepared in 63-73% yields from several simple cycloalkyl and aryl alkyl ketones by reaction at room temperature with per-benzoic acid. The larger radical of the ketone appears as the alcohol fragment of the ester. Cyclic ketones are oxidized by potassium persulfate and sulfuric acid to esters from which o>-hydroxy aliphatic esters are obtained upon hydrolysis and reesterification. Peracetic acid in acetic anhydride converts salicylaldehyde to o-hydroxyphenyl formate (88%). ... 

Acetic anhydride is often used to prepare acetate esters from alcohols and AT-substituted acetamides from amines. For example, aspirin (acetyl-salicylic acid) is prepared commercially by the acetylation of o-hydroxy-benzoic acid (salicylic acid) with acetic anhydride. Acetaminophen, a drug used in over-the-counter analgesics such as Tylenol, is prepared by reaction of p-hydroxyaniline with acetic anhydride. Note that the more nucleophilic -NH2 group reacts, rather than the less nucleophilic -OH group. 

Acetylation, formylatlon, and benzoylation of a variety of primary and secondary alcohols with the respective acids (acetic acid or anhydride, ethyl formate, and benzoic anhydride) can be achieved under the catalysis of BiCls, Bi(OCOCF3)3, or Bi(OTf)3 (Scheme 14.97) [194—196]. The O-acylahon of phenols is also promoted by these Lewis acids. Among the bismuth(III) salts employed, Bi(OTf)3 is the most effechve in terms of reaction condihons and yields of the esters. The Bi(OTf)3-acid anhydride procedure is apphcable to the acylahon of sterically demanding or tertiary alcohols and phenols. Treatment of terhary or benzylic bromides with Bi(OCOR)3 (R=Me, Ph) affords the corresponding esters [197]. In the presence of a catalytic amount of 612(804)3, the esterificahon of cis-(-)-thujopsene with a series of C2-C8 acids proceeds in moderate yield [198]. 

The reaction catalysed by 16 was an esterification with benzoic anhydride and the best kinetic resolution obtained (s = 67) with benzylic alcohol 19 was at - 40 °C. A value of 67 is very good for a kinetic resolution. However, exceptional results were obtained using phosphine 18. This catalyst is effective with a variety of alcohols and conditions. The best result was obtained with 20, AC2O and, crucially, catalyst which had been recrystallised to >99.9% ee. In this instance s = 390 ... 

Alcohol oxidations using acid anhydrides, such as acetic anhydride and benzoic anhydride, and phosphorus pentoxide with DMSO, have also been found to proceed in mild conditions to give the corresponding carbonyl compounds in good yields.27-29 The method is general and is especially useful for sterically hindered hydroxyl groups however, the reactions often suffer from concomitant formation of methylthiomethyl ether by-products. 

Write equations to show the reaction of benzoic anhydride with (a) water, (b)ethyl alcohol, and (c) aniline. 

Ultrasound has been used in the acetylation of a range of alcohols in dibutylim-idazolium bromide [197]. Generally a 5 to 10 times enhancement in the reaction rate is observed when compared with the equivalent silent reaction. 1,3-diaUcylimidazolium benzoate ionic liquids have been used in the benzoylation of glucose with benzoic anhydride (Scheme 5.2-80) [198]. The reaction was found to... 

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