Electrophilic 1,5-addition of acyl chlorides to the azocyclopropane system of spiro(1-pyrazoline-3,1'-cyclopropanes)

Article abstract of DOI:10.1007/BF00696321

1-Pyrazolines 1-4, which contain a spiro cyclopropane fragment at the adjacent azo group, react selectively with acetyl(benzoyl) chloride or acetic anhydride in the presence of AlCl3 to give high yields of the corresponding 1-acyl-3-(2-chloroethyl)-2-pyra