Benzyl Bromide → phenylmethyl (2RS,3S)-3-amino-2-hydroxyheptanoate

Participants

Reaction Steps

To 13.1 g (50 mmol) of (2RS,3S)-2-hydroxy-3-[N-(2-methyl-2-propyloxycarbonyl)amino]heptanoic acid synthesized in accordance with the method described in Reference Example 11 and 100 ml of suspension of dimethylfomiamide of 6.3 g (75 mmol) of sodium hydrogen carbonate, 20 ml of dimethylformamide solution of 9.4 g (55 mmol) of benzyl bromide was added and stirred at the room temperature for 18 hours. The reaction solution was added with ethyl acetate and washed with water twice and washed with saturated brine once. The resultant organic extracted layer was dried over anhyrous sodium sulfate and then the solvent was distilled away under reduced pressure, whereby the crude product of phenylmethyl (2RS,3S)-2-hydroxy-3-[N-(2-methyl-2-propyloxycarbonyl) amino]heptanoate was obtained. To the obtained phenylmethyl (2RS,3S)-2-hydroxy-3-[N-(2-methyl-2-propyloxycarbonyl)amino]heptanoate, 100 ml of 4N hydrogen chloride-ethyl acetate were added and was left alone at room temperature for one hour and thereafter the reaction solution was concentrated under reduced pressure. The residue was dissolved in water and washed with diethyl ether twice and the water layer was made basic with addition of sodium carbonate and was extracted with ethyl acetate three times. The organic layer was washed with saturated brine and dried over anhydrous sodium sulfate and, the solvent was distilled away from the reaction mixture under reduced pressure, whereby 9.3 g of phenylmethyl (2RS,3S)-3-amino-2-hydroxyheptanoate was obtained.

Provenance & Evidence