Patent ID: 8889880

Claim:
A process for preparing a compound of the formula or a pharmaceutically acceptable salt thereof; wherein Ar 1 is 4-hydroxyphenyl; R 1 is hydrogen, alkyl, arylalkyl or a pro-drug forming group; R 2 is selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 3 is optionally substituted alkyl; R 4 is optionally substituted alkyl or optionally substituted cycloalkyl; R 5 and R 6 are each independently selected from the group consisting of optionally substituted alkyl and optionally substituted cycloalkyl; R 7 is optionally substituted alkyl; and n is 1, 2, 3, or 4; wherein the process comprises the step of treating a compound of formula A with triethylsilyl chloride and imidazole in an aprotic solvent, where R 8 is C1-C6 unbranched alkyl or the step of treating a compound of formula B with a base and a compound of the formula ClCH 2 OC(O)R 2 in an aprotic solvent at a temperature from about −78° C. to about 0° C.; wherein the molar ratio of the compound of the formula ClCH 2 OC(O)R 2 to the compound of formula B from about 1 to about 1.5, where R 8 is C1-C6 unbranched alkyl or the steps of a) preparing a compound of formula (E1) where X 1 is a leaving group from a compound of formula E and b) treating a compound of formula C under reducing conditions in the presence of the compound of formula E1, where R 8 is C1-C6 unbranched alkyl or the step of treating compound D with a hydrolase enzyme, where R 8 is C1-C6 unbranched alkyl or the step of treating the silyl ether of compound F with a non-basic fluoride reagent or the step of treating a compound of formula G with an acylating agent of formula R 4 C(O)X 2 , where X 2 is a leaving group or the steps of c) forming an active ester intermediate from a compound of formula H and d) reacting the active ester intermediate with a compound of the formula I or a combination thereof.