Process for preparing ergoline derivatives

A process for preparing an ergoline derivative of the formula I:

• ##STR5## wherein R represents a hydrogen atom or a C.sub.1 -C.sub.3 alkyl group;
• R.sub.1 represents a hydrogen atom, chlorine, bromine atom or a methyl group;
• either R.sub.2 and R.sub.3 represent hydrogen atoms or R.sub.2 and R.sub.3 together represent a chemical bond;
• R.sub.4 represents a hydrocarbon group having from 1 to 4 carbon atoms selected from the group consisting of alkyl, cycloalkyl, ethylenically unsaturated and acetylenically unsaturated groups;
• each of R.sub.5, R.sub.6, R.sub.8 and R.sub.9 independently represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, a phenyl group or a cycloalkyl group having from 3 to 7 carbon atoms and n is 0, 1 or 2, which process comprises reacting an ergoline of the formula II with an .alpha.-halogen derivative of the formula III:
• ##STR6## wherein n, R, R.sub.1, R.sub.2, R.sub.3, R.sub.5, R.sub.6, R.sub.8 and R.sub.9 have the above given meanings, R.sub.10 and R.sub.11 independently represent a C.sub.1 -C.sub.4 alkoxy group or an amino group NHR.sub.7 wherein R.sub.7 is as defined above, X represents a halogen atom, R'.sub.4 represents a hydrocarbon group having from 1 to 4 carbon atoms selected having from 1 to 4 carbon atoms selected from the group consisting of alkyl, cycloalkyl, ethylenically unsaturated and acetylenically unsaturated groups or a N-protecting group and, if necessary, converting the resultant compound of the formula IV:
• ##STR7## wherein R, R.sub.1, R.sub.2, R.sub.3, R.sub.5, R.sub.6, R.sub.8, R.sub.9 and n are as defined above, R.sub.10 and R.sub.11 independently represent a C.sub.1 -C.sub.4 alkoxy group or an amino group NHR.sub.7 wherein R.sub.7 is as defined above and R'.sub.4 is a N-protecting group into a compound of the formula IV in which R'.sub.4 is a C.sub.1 -C.sub.4 hydrocarbon group selected from the group consisting of alkyl, cycloalkyl, ethylenically unsaturated and acetylenically unsaturated groups by deprotection and alkylation, if necessary converting the compound of the formula IV in which R.sub.10 and R.sub.11 both represent an alkoxy group into a compound of the formula IV in which R.sub.10 and R.sub.11 are both amino groups by ammonolysis;
• and cyclizing a said compound of the formula IV in which at least one of R.sub.10 and R.sub.11 represents an amino group NHR.sub.7 is as defined above.