反应详情

25 g of raw urea obtained by step (a) are suspended in 150 ml of water and heated under reflux for 2 hours. After allowing the temperature of the mixture to return to room temperature, the aqueous solution is extracted with ether. The aqueous phase is separated and made alkaline by adding concentrated ammonia. The resulting precipitate is separated by suction, washed with water and dried. 11.8 g of 2-(dicyclopropylmethylamino) oxazoline are thus recovered, melting at 105°-106° C. A mixture of the latter with N-(dicyclopropylmethyl) N'-(β-chloroethyl) urea gives a decrease of the melting point.

1. temperatureheated
2. temperatureunder reflux for 2 hours
3. customto return to room temperature
4. extractionthe aqueous solution is extracted with ether
5. customThe aqueous phase is separated
6. additionby adding concentrated ammonia
7. customThe resulting precipitate is separated by suction
8. washwashed with water
9. customdried
10. custom11.8 g of 2-(dicyclopropylmethylamino) oxazoline are thus recovered
11. additionA mixture of the latter with N-(dicyclopropylmethyl) N'-(β-chloroethyl) urea
12. customgives a decrease of the melting point