During a study of methods for the preparation of the combined fi-blockerlvasodilator prizidilol (3-[2-[3-(tert-butylamino)-2-hydroxypropoxy] phenyl]-6-hydrazinopyridazine, 1) and analogues, our interest was aroused by a report that reaction of 3, 6-dichloropyridazine (2) with resorcinol and hydroquinone in the presence of aluminum chloride gave the 3-chloro-6- (2, 4-and 2, 5-dihydroxyphenyl) pyridazines, 3a and 3b, respectively.'This reaction proved ...