Process for the preparation of imidazoleacetic acid derivatives

A process for preparing an imidazoleacetic acid derivative of the formula ##STR7## wherein R.sub.1 is hydrogen;

• C.sub.1-24 -alkyl;
• C.sub.5-7 -cycloalkyl;
• C.sub.7-14 -aralkyl;
• C.sub.6-14 -aryl;
• a C.sub.6-10 -aromatic, mono- or bi-cyclic heterocycle of 5-10 total ring atoms, 1-3 being O, N or S atoms, the remainder being C-atoms;
• substituted C.sub.6-14 -aryl or said aromatic heterocycle each substituted by 1-3 halogen atoms, up to three C.sub.1-4 -alkyl groups, a nitro group, up to three C.sub.1-4 -alkoxy groups, a C.sub.1-4 -alkoxycarbonyl group or CF.sub.3 ;
• amino;
• or amino substituted by C.sub.1-24 -alkyl, C.sub.5-7 cycloalkyl, C.sub.7-14 -aralkyl or C.sub.6-14 aryl;
• R.sub.2, independently, is hydrogen, alkyl, cycloalkyl, aralkyl, aryl, or a heterocyclic group, all as defined above for R.sub.1 ;
• or
• R.sub.1 and R.sub.2 together are C.sub.4-7 alkylene forming a ring with their connecting C-N bond;
• and
• R.sub.3 is C.sub.1-10 -alkoxy, C.sub.7-14 -aralkoxy, amino, mono or di-C.sub.1-4 -alkylamino, pyrrolidino, piperidino, morpholino, arylamino, heteroarylamino, or substituted arylamino or substituted heteroarylamino, each of which is substituted in the aryl portion as recited above for R.sub.1 ;
• comprising reacting a corresponding amidine or guanidine of the formula ##STR8## or a reaction compatible acid addition salt thereof wherein
• R.sub.1 and R.sub.2 are as defined above with an acetoacetic acid derivative of the formula ##STR9## wherein R.sub.3 is as defined above and
• X is fluorine, chlorine, bromine, or iodine, and
• R.sub.4 is tri-C.sub.1-4 -alkyl or tri-C.sub.7-10 -aralkylsilyl, C.sub.1-4 -alkyl, or C.sub.7-10 -aralkyl