Water → HCID 21536154, compound

1-(4-Chlorophenyl)-1-hydroxyurea (34 grams; 0.18 mole) dissolved in aqueous sodium hydroxide (200 ml; 2 N) are charged into a glass reaction vessel equipped with a mechanical stirrer and thermometer. The solution is cooled to a temperature of 10° to 15°C and ethyl chloroformate (17 ml) is slowly added with stirring. After the addition is completed stirring is continued for a period of about 1/2 hour. Water (200 ml) is then added to the reaction mixture with stirring and the resulting mixture is poured into 3 liters of water. The resulting aqueous solution is then filtered and the filtrate is cooled and acidified with concentrated hydrochloric acid to form a precipitate. The precipitate is recovered by filtration and is dried. The resulting product is then dissolved in a 100:5 mixture of methylene chloride and tetrahydrofuran and the solution is dried over anhydrous magnesium sulfate. The dried solution is then stripped of solvent under reduced pressure to yield the desired product 2-(4-chlorophenyl)-1,2,4-oxadiazolidin-3,5-dione.

1. additionare charged into a glass reaction vessel
2. customequipped with a mechanical stirrer
3. additionis slowly added
4. additionAfter the addition
5. stirringis completed stirring
6. stirringwith stirring
7. filtrationThe resulting aqueous solution is then filtered
8. temperaturethe filtrate is cooled
9. customto form a precipitate
10. filtrationThe precipitate is recovered by filtration
11. customis dried
12. dissolutionThe resulting product is then dissolved in a 100:5 mixture of methylene chloride and tetrahydrofuran
13. dry with materialthe solution is dried over anhydrous magnesium sulfate

ORD record

ord-3abc90eca74b44899bd4494f8e0476b9

Source dataset

uspto-grants-1976_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03959478