Hydrochloric Acid → HCID 12043747, compound

Temperature

0 °C

10 ml of water was added to 2.00 g (8.57 mmol) of (R)-4-t-butoxycarbonylamino-3-hydroxybutanohydrazide (optical purity: >99.9%e.e.), and the mixture was cooled to 0° C. A 0.89 g (8.57 mmol) of 35% HCl was added thereto dropwise over 10 min, and then an aqueous solution of 0.59 g (8.57 mmol) of sodium nitrite dissolved in 2.0 ml of water was further added thereto dropwise slowly. After the reaction mixture was stirred for 1 hour at that temperature, the thus prepared reaction mixture was added to 10 ml of warm water (50° C.) dropwise over 1 hour. After the addition, the mixture was further stirred for 1 hour, cooled to room temperature, and then extracted thrice with a 20 ml portion of ethyl acetate. The extracted ethyl acetate was then concentrated to give 1.06 g of a crude product. The crude product was subjected to column chromatography (ethyl acetate) to obtain 0.96 g (52%) of the title compound. Melting point: 115.5° C. Optical purity: >99.9%e.e.

1. additionwas further added
2. customthe thus prepared reaction mixture
3. additionAfter the addition
4. stirringthe mixture was further stirred for 1 hour
5. temperaturecooled to room temperature
6. extractionextracted thrice with a 20 ml portion of ethyl acetate
7. concentrationThe extracted ethyl acetate was then concentrated
8. customto give 1.06 g of a crude product

ORD record

ord-70e06e2664834894b796bc7b15acdc32

Source dataset

uspto-grants-2002_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06403804B1