Hydrochloric Acid → (R)-2-(3,4-Dichloro-phenylamino)-propionic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 6.00 g (22.00 mmol) 3,4-dichloroiodobenzene, 2.94 g (33.00 mmol) D-alanine, 0.42 g (2.20 mmol) copper(I) iodide, 0.96 g (4.40 mmol) 2-hydroxybenzaldehyde phenylhydrazone, 14.00 g (66.00 mmol) tri-potassium phosphate in 32 ml of N,N-dimethylformamide was stirred at 80° C. for 16 h under argon, then after cooling diluted with water and acidified to pH 3 by addition of 25% aq. HCl solution. The mixture was extracted with EtOAc (3×), the organic phases were washed with brine, dried (Na2SO4), filtered and evaporated. Flash chromatography (SiO2; dichloromethane/MeOH 95:5 to 4:1) afforded 3.11 g (60%) of the title compound (as 81:19 mixture of the (R) and (S) stereoisomers, BGB-175*0.25 column) as light brown solid. MS: 231.9 (M−H−, 2Cl).

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