Bromide ion → (S)-2-(4-bromobenzyl)amino-3-methylbutyric acid

참여 물질

반응 조건

반응 단계

52 mL (0.21 mol) of N,O-bistrimethylsilylacetamide is added under nitrogen atmosphere to a mixture made up of 23.5 g (0.20 mol) of L-valine and 38.5 mL (0.22 mol) of diisopropylethylamine in 12.5 mL of DMF. After 1 h at 80° C. the suspension changes to a clear solution. Then, in portions and controlling exothermy, 50 g (0.20 mol) of 4-bromobenzylo bromide is added and left to react at 80° C. for 2 h. The mixture is cooled to 20-25° C., 250 mL of toluene and a solution made up of 250 mL of water and 80 mL of NaOH 40% are added. The resulting aqueous phase is washed twice with 100 mL of AcOEt, the remains of solvent distilled and taken to pH 6-7 with HCl 3N. The solid obtained is filtered with 250 mL of IPA to give 43.9 g (76.5%) of N-(4-bromobenzyl)-L-valine.

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