Abstract A series of new pyridazines bearing ortho-directing groups at C-4 (protected/activated amino or carboxylic acid functionalities) was prepared and their metalation with lithium 2, 2, 6, 6-tetramethylpiperidide was studied. Reactions of the ortho- lithiated species thus obtained with aldehydes as electrophiles opens an access to 4, 5- disubstituted pyridazines 3, 4, 14, and 15.
