Patent / 1963
The use of chloroformate esters, carboxylic salt or acid, and the alc. was claimed to give an improved esterification process. Thus, to 14.5 g. BzONa in 100 cc. Me2CO at 0.degree. 10.9 g. ClCO2Et in 10 cc. Me2CO was added, stirred 1/2 hr., then 18 g. MeOH and 2 cc. pyridine stirred in until gas evolution stopped, reflux continued 2 hrs., then distd. to yield 43.6% BzOMe, b. 198-200.degree.. Similarly were prepd.: BzOEt, b. 210-13.degree., 92% yield; AcOEt (at -20.degree. with 1.4 cc. Et3N instead of pyridine), b. 75-7.degree., 88%; iso-Pr palmitate, m. 42-3.degree., 44%; diethylaminoethyl benzoate, in Me2CO 48%, in dimethyl formamide 89%; Et malonate, b. 192-200.degree. in tetrahydrofuran 87%; hydriodide of diethylamino ester of penicillin G, m. 170-8.degree., 74%; hydriodide of the diethyl amino ester of penicillic acid, 40%; Me ester of gibberellic acid, m. 208-10.degree. (C6H6-MeOH); Me ester of indoleacetic acid, 87%. In MeCN solvent: Na salt of 21-prednisolone phosphate, 66% yield; Na salt of 9.alpha.-fluoro-16.beta.-methylprednisolone, 75%; Na salt of 21-prednisolone sulfate; Na salt of 9.alpha.-fluoro-16.alpha.-methyl- prednisolone sulfate, 79%. In Me2CO solvent: testosterone propionate, 46%; Me ester of N-acetylpenicillamine, 23%, methandriol diacetate, 39%; Et ester of the diacetate of cholic acid, 63%; ethyl phenaceturate 81%, benzoate of estradiol. Similar reaction with Ca pantothenate and chloramphenicol (I) gave a cryst. product not further identified. K palmitate and I gave a product, m. 89-90.degree.