5,5´-Diphenylhydantoin
Chemicals:
Benzil (Dibenzoyl)
Harnstoff (H2NCONH2)
KOH
Ethanol
Methanol
Reaction:
A 250ml roundbottomflask equipped with stirrer, dropping-funnel and heater is filled with a solution of 4,2 g (20mmol) Benzil in 100ml Ethanol. Over the dropping funnel a solution of 5,61 g (0,1mol) KOH in 10 ml Water is added and the mixture is heated to reflux. After 2 hours the mixture is cooled down to RT and 300ml water is added. Filter the solution and saturate it with solid CO2.
A precipetate should form, collected by sucktion filtration and recrystallized from minimum amount of methanol.
Analytic:
yield : 50-60%
FP: 293,5°C
Lit.:
R. C. Hayward, J. Chem. Educ. 60 (1983) 512.
H. Beyer und W. Walter, Lehrbuch der organischen Chemie, 19. Aufl., S.669, S. Hirzel Verlag, Stuttgart 1981.