Sodium Chloride → 4-T-butylsemicarbazide

To a solution of 30 g of hydrazine hydrate (80%) in 100 ml of ethanol was added dropwise 34 ml of t-butyl isocyanate under ice-cooling, followed by stirring for 1 hour. After stirring at room temperature for an additional 3 hours, a saturated aqueous solution of sodium chloride was added to the reaction solution. The mixture was extracted three ,times with ethyl acetate, and the organic layer was distilled under reduced pressure. To the residue was added 65 ml of a 10% hydrochloric acid aqueous solution. After washing with chloroform, 16 ml of a 50% aqueous solution of sodium hydroxide was added thereto, and sodium chloride was further added thereto The mixture was extracted with ethyl acetate, and the organic layer was dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure. Recrystallization of the residue from n-hexane/ethyl acetate (9:1 by volume) to obtain 36 g of 4-t-butylsemicarbazide (melting point:109 -110 ° C.).

1. temperaturecooling
2. stirringAfter stirring at room temperature for an additional 3 hours
3. extractionThe mixture was extracted three
4. distillationwith ethyl acetate, and the organic layer was distilled under reduced pressure
5. additionTo the residue was added 65 ml of a 10% hydrochloric acid aqueous solution
6. washAfter washing with chloroform, 16 ml of a 50% aqueous solution of sodium hydroxide
7. additionwas added
8. additionsodium chloride was further added
9. extractionThe mixture was extracted with ethyl acetate
10. dry with materialthe organic layer was dried over anhydrous sodium sulfate
11. customThe solvent was removed by distillation under reduced pressure
12. customRecrystallization of the residue from n-hexane/ethyl acetate (9:1 by volume)

ORD record

ord-2b0a114b7ac948acb1351e9ba35b6cd2

Source dataset

uspto-grants-1991_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05064751