PYRAZOLINES: PART II

Product analysis has been carried out on the pyrolysis reaction in the liquid and vapor phase of 4- and 5-methyl-3-carbomethoxy-Δ 2 -pyrazolines and 3-methyl-3-carbomethoxy-Δ 1 -pyrazoline. The proportion of cyclopropane product was found to be greater than earlier reports had indicated and was higher for the vapor-phase pyrolysis than for the liquid-phase reaction. Vapor-phase pyrolysis of Δ 2 -pyrazolines was found to require a catalyst, such as potassium hydrogen phosphate, which is believed to make possible the transformation of the Δ 2 -pyrazoline into the pyrolyzable Δ 1 -pyrazoline.