2-Amino-3,3-dimethylbutanoic acid → D-tert-leucine

Temperatur

28 °C

(DL)-tert-Leucine (15 g, 0.1145 mol) was dissolved in water (180 mL). To the solution was added dibenzoyl-d-tartaric acid monohydrate (21.5 g, 0.057 mol) and stirred for 24 hours at 28° C. (±3). The reaction mixture was filtered to collect L-tert-leucine dibenzoyl-d-tartrate salt. The filtrate was reserved for isolating D-tert-leucine later. The tartrate salt was added to water (150 mL) followed by concentrated sulphuric acid (3 mL) and stirred for 4 hours. Liberated dibenzoyl-d-tartaric acid was collected and dried (19.8 g, 92% yield). The filtrate was washed with diisopropyl ether (50 mL) to remove any traces of dibenzoyl-d-tartaric acid, cooled to 5° C. and treated with a saturated solution of barium hydroxide till the pH was neutral. It was filtered to remove the precipitated barium sulphate. The filtrate was concentrated under reduced pressure to remove all the solvent. The residue obtained was stirred with acetone (15 mL×2), filtered and dried to obtain colorless solid L-tert-leucine (6 g, 80% yield, 99% chemical purity, 99.9% chiral purity).

1. filtrationThe reaction mixture was filtered
2. customto collect L-tert-leucine dibenzoyl-d-tartrate salt

ORD-Eintrag

ord-ddb0d8bc251843a794ab7a67a49c4307

Quelldatensatz

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08835676B2