A process for the preparation of corticosteriod esters of the formula ##STR1## in which ---- signifies that a double bond can be present; X is hydrogen, chlorine or fluorine; R.sub.1 is hydrogen, fluorine, chlorine or methyl, which may be either .alpha. or .beta.; R.sub.2 is halogen, oxo or hydroxyl; or R.sub.3 is hydrogen, .alpha.-methyl or .beta.-methyl; or R.sub.2 and X jointly form an epoxide group; R.sub.4 is an acyl group of the formula RCO, in which R is one of the following (i) an alkyl group containing 1 to 16 carbon atoms, whether straight-chained, branched or cyclic; (ii) an aralkyl group of 7 to 8 carbon atoms; (iii) a phenyl group; R.sub.5 is hydroxyl or R.sub.6 ; where R.sub.6 is hydrogen, one or two halogen atom substituents or OR.sub.7, where R.sub.7 is an acyl group of the formula R'CO in which R', which can be identical or different to R in the same molecule, is one of the following: (i) an alkyl group of 1 to 16 carbon atoms, whether straight-chained, branched or cyclic; (ii) an aralkyl group of 7 to 8 carbon atoms; or (iii) a phenyl group. which comprises esterifying a compound of the formula ##STR2## wherein X, R.sub.1, R.sub.3 and R.sub.5 are as defined above, and R.sub.8 is trihaloacetate, halogen or oxo, or jointly forms an epoxide group with X; at the 17-position only, or at the 17- and 21-positions when R.sub.5 in formula III is hydroxyl, the said esterification being carried out with the anhydride of the acid containing the group desired.
一种制备糖皮质激素酯的方法,其中该酯的
化学式为##STR1## 其中——表示可以存在双键;X为氢、
氯或
氟;R.sub.1为氢、
氟、
氯或甲基,可以是.alpha.或.beta.;R.sub.2为卤素、氧代或羟基;或者R.sub.3为氢、.alpha.-甲基或.beta.-甲基;或者R.sub.2和X共同形成环氧基团;R.sub.4为
化学式RCO的酰基,其中R为以下之一:(i) 1至16个碳原子的烷基,无论是直链、支链还是环状;(ii) 7到8个碳原子的芳基烷基;(iii) 苯基;R.sub.5为羟基或R.sub.6,其中R.sub.6为氢、一个或两个卤素原子取代基或OR.sub.7,其中R.sub.7为
化学式R'CO的酰基,其中R'可以与同一分子中的R相同或不同,为以下之一:(i) 1至16个碳原子的烷基,无论是直链、支链还是环状;(ii) 7到8个碳原子的芳基烷基;或(iii) 苯基。该方法包括酯化以下化合物的步骤##STR2## 其中X、R.sub.1、R.sub.3和R.sub.5如上定义,R.sub.8为三卤代
乙酸酯、卤素或氧代,或与X共同形成环氧基团;仅在17位或在R.sub.5为羟基的情况下在17位和21位进行酯化反应,所述酯化反应是用所需
羧酸的无
水酸酐进行的。