Process for the preparation of N-substituted esters of 9,10-dihydrolysergicacids

In a process for the preparation of N-substituted esters of 9,10-dihydrolysergic acids of the formula:

• ##STR5## capable of being converted to pharmacologically active compounds wherein R.sub.1 is an alkyl group of 1-5 carbon atoms, an alkenyl group of 2-5 carbon atoms, or a cycloalkyl group of 3-5 carbon atoms,
• R.sub.2 is hydrogen or an alkoxy group of 1-3 carbon atoms, and
• X is hydrogen or halogen,
• the improvement which comprises carrying out the alkylation of the compounds of the formula:
• ##STR6## wherein R is hydrogen or a hydrolyzable organic group capable of being hydrolyzed in alkaline medium,
• X is hydrogen or halogen, and
• R.sub.2 has the meaning as stated above,
• with a compound of the formula:
• R.sub.1 Y (III)
• wherein
• R.sub.1 has the meaning as stated above,
• Y is halogen or sulphate,
• in the presence of a catalyst for phase transition of the formula:
• Z.sub.4 QA (IV)
• wherein
• Z represents the same or different alkyl, cycloalkyl, aryl, arylalkyl or alkylaryl groups with 1-16 carbon atoms,
• Q is an quaternary nitrogen or phosphorus atoms, and
• A is an anion,
• in a two phase aqueous alkali medium-organic solvent system wherein the organic phase includes a hydrocarbon which is immiscible with water.