反应详情

温度

160 °C

Urea (115 g, 1915 mmol) was melted in a 500 mL 3 neck flask under nitrogen and heated at 160° C. The crude aminobenzaldehyde from step 1 (8.4 g) was added, one of the necks of the flask was opened to the atmosphere and the temperature of the oil bath raised to 190° C. When the bath temperature reached 175° C., a white precipitate was observed. The mixture was cooled and water (400 mL) was added. It was stirred for 15 minutes then filtered through a sintered glass frit. The collected solids were dried by azeotroping with toluene at reduced pressure (3×300 mL) then further dried under high vacuum at 70° C. The crude material was used without further purification.

1. temperaturethe temperature of the oil bath raised to 190° C
2. customreached 175° C.
3. temperatureThe mixture was cooled
4. filtrationthen filtered through a sintered glass frit
5. customThe collected solids were dried
6. customby azeotroping with toluene at reduced pressure (3×300 mL)
7. customthen further dried under high vacuum at 70° C
8. customThe crude material was used without further purification