2-Amino-3-methylpentanoic acid → (2S,3S)-2-Chloro-3-methylvaleric Acid

78.7 g (0.6 mole) 2-amino-4-methyl pentanoic acid (preparation example 1) or 0.6 mole 2-amino-3-methyl pentanoic acid (preparation example 2) was dissolved in 700 ml 6N HCl. Total 91 g (1.3 mole) sodium nitrite powder was divided into several portions and were added To the solution in a span of 2 hours while an ice bath was used. The reaction was carried out for 5-6 hours at 0°-5° C., the reaction mixture was extracted with ethyl ether for three times, washed with saturated NaCl aqueous solution, dried over MgSO4, concentrated, and distilled under reduced pressure twice to yield a transparent liquid product. Yield: I-1: 74.7%; I-2: 69.5%. mp: I-1:92° C./3 mmHg; I-2:88° C./3 mmHg. The optical rotation [α]25D (chloroform): I-1:-I3.98 (neat liquid); I-2: -4.78 (neat liquid).

1. additionwere added To the solution in a span of 2 hours while an ice bath
2. extractionthe reaction mixture was extracted with ethyl ether for three times
3. washwashed with saturated NaCl aqueous solution
4. dry with materialdried over MgSO4
5. concentrationconcentrated
6. distillationdistilled under reduced pressure twice
7. customto yield a transparent liquid product
8. custom92° C./3 mmHg
9. custom88° C./3 mmHg

ORD record

ord-d77fba320d5548ca8eca3d378b24a10a

Source dataset

uspto-grants-1996_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05495037