反应详情

温度

150 °C

103 g of the amido acid of maleic acid anhydride and N-methyl aniline are dissolved in 200 g of butyrolactone. 119 g of phenyl isocyanate are then added dropwise at 20° to 25° C. 0.2 g of triethylene diamine are then added and the mixture is stirred for 2 hours at 50° C., for 2 hours at 100° C. and for 4 hours at 150° C. The condensation and ring-forming reaction are accompanied by the elimination of carbon dioxide. On completion of the reaction, 112 g of the hydantoin melting at 191° C. crystallise out on cooling. Another 17 g are obtained from the filtrate by precipitation with water and recrystallisation from ethanol/dioxane (3:1). After another recrystallisation from ethanol/dioxane, 1,3-diphenyl-5-(N-methyl-N-phenylaminocarbonylmethyl)-hydantoin is obtained in the form of almost colourless crystals melting at 195° to 196° C. In the IR-spectrum, the compound shows the bands typical of hydantoins at 1720 and 1780 cm-1 and a band corresponding to amide at 1645 cm-1.

1. customThe condensation
2. customring-forming
3. customreaction
4. customcrystallise out
5. temperatureon cooling
6. customAnother 17 g are obtained from the filtrate by precipitation with water and recrystallisation from ethanol/dioxane (3:1)
7. customAfter another recrystallisation from ethanol/dioxane