PREPARATION OF N-6 DEMETHYLATED, 9-10-DIHYDROLYSERGIC ACID ALKYL ESTERS

摘要

A process for producing N-6 demethylated 9,10-dihydrolysergic acid alkyl ester is described, which comprises a step of N-6 demethylation of 9,10-dihydrolysergic acid alkyl esters with chloroformate and wherein the N-6 demethylation step is performed in the presence of an organic catalyst. Further, a process for converting a compound of formula (I) (DHLSAIkyl) into a compound of formula (Il) (DHLSAIkyl-F) comprises the steps of: providing (and maintaining) a reaction medium free of water and/or HCI, and reacting DHLSAIkyl with chloroformate in said reaction medium free of water and/or HCI, to obtain the compound of formula (Il) (DHLSAIkyl-F).