IMPROVED PROCESS FOR THE MANUFACTURE OF 1,2-DISUBSTITUTED HEXAHYDROPYRIDAZINE-3-CARBOXYLIC ACIDS AND ESTERS THEREOF

摘要

The invention relates to an improved process for the manufacture of 1,2-disubstituted hexahydro-pyridazine-3-carboxylic acids and esters thereof by reacting N,N’-disubstituted hydrazine with 2,5-dihalogenated valeric acids and thereof by means of phase transfer catalysis. Said pyridazine carboxylic acids and esters thereof can be used as intermediates for the production of pharmaceutical products