Patent ID: 8785642

Claim:
A process for the preparation of a compound of the formula wherein n is 1, 2, 3 or 4; and R1 is H or a protecting group, comprising (B) reacting a compound of formula (IV) wherein R1 is a protecting group with a mixture of a reagent of the formula (R2O) 2 HC—N(CH 3 ) 2 (V), wherein R 2 is (C 1 -C 6 )alkyl, and pyrrolidine, wherein reagent (V) is used in a molar excess of 1.5 or more equivalents and the pyrrolidine is used in a molar excess of 4.0 or more equivalents over a compound of formula (IV); and optionally removing the protection group in a compound of formula (VI) to give a compound of formula ((VI) wherein R1 is H.