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

Participants

Reaction Steps

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).

Provenance & Evidence