Sulfuric Acid → (R)-2-hydroxy-4-methylpentanoic acid

While heating and stirring 100 ml of aqueous solution of 14 g of sodium nitrite at 90° C., 400 ml aqueous solution of 0.5N sulfuric acid of 25 g of D-leucine was added over 45 minutes. After dripping, the solution was stirred for 15 minutes until foams were no longer generated. The reaction solution was concentrated to 200 ml in vacuo, and the obtained residue was extracted with diethyl ether. The diethyl ether layer was washed one with 1N hydrochloric acid, and twice with saturated brine sequentially, and dried over sodium sulfate anhydride, and concentrated in vacuo. The obtained oily residue was left over, crystallized, and the captioned compound was obtained. Yield: 14.50 g.

1. temperatureWhile heating
2. concentrationThe reaction solution was concentrated to 200 ml in vacuo
3. extractionthe obtained residue was extracted with diethyl ether
4. washThe diethyl ether layer was washed one with 1N hydrochloric acid
5. dry with materialtwice with saturated brine sequentially, and dried over sodium sulfate anhydride
6. concentrationconcentrated in vacuo
7. waitThe obtained oily residue was left over,
8. customcrystallized
9. customthe captioned compound was obtained

ORD record

ord-9afe7aeb4bb045bdbd2974e0eb1bac46

Source dataset

uspto-grants-1997_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05594006