摘要 |
<p>A process for synthesizing a coumpond of formula (I) or a pharmaceutically acceptable salt or ester thereof, wherein each P independently represents H or a protecting group, and R<1> and R<2> independently represent H, C1-10 alkyl, aryl or heteroaryl, or substituted C1-10 alkyl, aryl or heteroaryl, comprising: reacting the compounds (II) or a pharmaceutically acceptable salt or ester thereof, and (III) or a pharmaceutically acceptable salt or ester thereof, wherein X represents OP(O)(OR)2, or OSO2R, wherein R represents C1-6 alkyl, aryl or perfluoro C1-6 alkyl, in the presence of an amine selected from the group consisting of: diisopropylamine (DIPA), dicyclohexylamine (DCHA), 2,2,6,6-tetramethylpiperidine (TMP), 1,1,3,3-tetramethylguanidine (TMG), 1,8-diazabicyclo[4.3.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene to produce a compound of formula (I).</p> |