Cinnamaldehyde reaction with hydrazine

Chrysene, 46, 95 Cinnamaldehyde, 46, 36 reaction with hydrazine, 47, 99 2,4,6-Collidine in hydrolysis of esters to acids, 46, 8... 

Chrysene, 45, 95 Cinnamaldehyde, 45, 36 48, 79 reaction with hydrazine, 47, 99 Cinnamic acids and derivatives, conversion to phenylcyclopropanes with lithium aluminum hydride,... 

Reaction of 2-isothiocyanato-/ra/w-cinnamaldehyde (110) with hydrazine gave the pyrazolo[l,5-c]quinazolines (111), presumably via the corresponding hydrazone and conjugate addition to the pyrazoline followed by cyclization [76JCS(P1)653]. 

A 500-ml, three-necked, round-bottom flask is equipped with a condenser, a dropping funnel, and a thermometer in the reaction mixture. In the flask is placed a mixture of 85% hydrazine (115 ml, 118 g) and 225 ml of 95% ethanol with a few boiling chips. The solution is brought to reflux (mantle) and cinnamaldehyde (100 g, 0.76 mole) is added dropwise over about 30 minutes followed by an additional 30 minutes of refluxing. A still head is attached to the flask and volatiles (ethanol, water, hydrazine hydrate) are slowly distilled at atmospheric pressure until the pot temperature reaches 200° (about 3 hours). Hereafter, phenylcyclopropane is collected over the range 170-180°. When the pot temperature exceeds 250°, the recovery is complete. The crude product (55-65 g) is washed twice with 50-ml portions of water and dried (anhydrous potassium carbonate). Distillation under vacuum through a short column affords the product, bp 60°/13 mm, 79-80°/37 mm, n f 1.5309, about 40 g (45%). 

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