A Method for the Esterification of Hindered Acids¹

Abstract

p-nitrobenzoyl chloride,29 2,3-di-O-methyl-D-mannose 1,4,6tri-p-nitrobenzoate was obtained: m.p. 192-194°, [ ]22 +66°( c 0.3, chloroform); lit.29 m.p. 194°, [a]n +65°(chloroform).(29) See ref. 12, p. 539.

Electrostatic catalysis by ionic aggregates: scope and limitations of Mg(ClO4)2 as acylation catalyst

“…reaction mixture was extracted with DCM to afford the product (428 mg, 75%), which was in full agreement with the spectral data (mp, IR, 1 H NMR and EIMS) of an authentic sample of 2 0 -naphthyl 2,2,2-trimethylacetate 38. tert-butyl-4-methyl phenyl acetate,6 4-bromophenyl acetate, 10 4-chlorophenyl acetate,39 4-acetoxyacetophenone,42 methyl-4-acetoxybenzoate, 37b 4-acetoxybenzoic acid, 37b 2-acetoxybenzoic acid, 37b benzene-1,2-diyl diacetate, 9d benzene-1,3-diyl diacetate, 37b benzene-1,4-diyl diacetate, 37b benzene-1,2,3-triyl triacetate, 42 N,O-diacetyl-L-tyrosine ethyl ester,43 N-benzoyl-O-acetyl-L-tyrosine ethyl ester,43 …”

The transmission of polar effects. Part VII. A proton magnetic resonance spectra study of substituted mesitylenes, durenes, anthracenes, and triptycenes

“…9-Bromoanthracene was prepared by bromination of anthracene (40) and gave, o n treatment with phenyl lithium and carboxylation, 9-anthroic acid (41). Methyl 9-anthroate was obtained by esterification of the acid by the action of trifluoroacetic anhydride and methanol (42). The reaction of anthrone with phenyl magnesium bromide gave 9-phenylanthracene (43).…”

A TFAA–H3PO4-mediated direct, metal-free and high-speed synthesis of aryl carboxylate esters from phenols

“…This can be achieved either via conversion of carboxylic acid to more reactive functional groups, such as anhydride [5][6][7] and acyl halide [8][9][10], or via in situ activation in the presence of coupling reagents. These include trifluoroacetic anhydride (TFAA) [11], 2-chloro-1-methylpyridinium iodide [12], BOP [13], DCC [14], PPE [15], N,N-bis(2-oxo-3-oxazolidinyl)phosphordiamidic chloride [16], CCl 4 /PPh 3 [17], diphenyl(1,2-benzisoxazol-3-yl)phosphate [18], Me 2 NSO 2 Cl [19], montmorillonite-Ti 4+ [20], metal triflates in [bmim]PF 6 [21], Mn(OAc) 3 [22], TiO(acac) 2 [23], diarylammonium arensulfonate [24], and several other condensing agents [25][26][27][28][29][30]. Some of these methods however, are associated with several drawbacks such as moderate yields, long reaction times, use of expensive reagents, and the use of volatile and environmentally harmful organic solvents.…”