HOMOLYTIC ALKOXYCARBONYLATION REACTIONS IN TWO-PHASE SYSTEMS 3. INTRODUCTION OF A SINGLE CARBOXYLIC ACID ESTER FUNCTION INTO CYANO- OR ALKOXYCARBONYL SUBSTITUTED N-HETEROAROMATICS

Article abstract of DOI:10.3987/R-1987-03-0731

Homolytic alkoxycarbonylation reactions with cyanopyridines 1a, 2a, 3a, alkyl pyridinecarboxylates 1b, 2b, 3b, 3c and ethyl 4-pyridazinecarboxylate 4 in presence of dichloromethane were studied.It is demonstrated that under these conditions multiple substitution in general is suppressed markedly.Thus, this experimentally simple procedure represents an efficient and versatile method for single-step preparations of alkyl cyanopyridinecarboxylates 7a, 8a, 9a, 10a.Furthermore, it provides convenient access to so far not available mixed esters 5b, 7b, 8b, 10b, 13, derived from 2,3-pyridine-, 2,4-pyridine-, 3,4-pyridine and 4,5-pyridazinedicarboxylic acid.