Le. Fisher et al., MILD HYDROLYSIS OR ALCOHOLYSIS OF AMIDES - TI(IV) CATALYZED CONVERSION OF PRIMARY CARBOXAMIDES TO CARBOXYLIC-ACIDS OR ESTERS, Canadian journal of chemistry, 72(1), 1994, pp. 142-145
Reaction of primary amides (e.g., 1a or 6-13) or O-methylhydroxamates
(1b and 1c) with a catalytic amount of TiCl4 and one equivalent of aqu
eous HCl converts these compounds in good yields to carboxylic esters
(when an alcohol is used as solvent) or to carboxylic acids (when 9:1
dioxane:H2O is used as solvent). These conversions are chemoselective
for primary amides: mono- and dialkyl amides are not affected by the r
eaction conditions. The hydrolysis conditions described do not comprom
ise the stereochemical integrity of an adjacent chiral center. This is
exemplified by the hydrolysis of naproxen amide (34) to naproxen (33)
without detectable racemization as determined by chiral HPLC.