Glycolic Acid → N-(hydroxyacetyl)alanine ethyl ester

Beteiligte Stoffe

Reaktionsschritte

One equivalent each of hydroxyacetic acid (10.0 g), dicyclohexylcarbodiimide, (L)-alanine ethyl ester hydrochloride and imidazole was stirred in 500 mL acetonitrile. The reaction mixture, initially at 0° C. was allowed to warm to room temperature overnight and then heated at 65° C. for 2 hours. After the addition of an equal volume of toluene, the reaction mixture was filtered and the solvent removed by rotovaping from the filtrate to give crude product. An aliquot of the crude product was chromatographed on silica gel to give N-(hydroxyacetyl)alanine ethyl ester (61% yield). 1H NMR (300 MHz, DMSO-d6 /TMS): δ1.19 (t , 3H, J=7.1 Hz), δ1.31 (d, 3H, J=7.2 Hz), δ3.83 (s, 2H), δ4.09 (d×q, 2H, J=1.2 and 7.1 Hz, irradiation in the methyl region eliminates the smaller coupling constant), δ4.32 (d×q, 1H, J=7.3 and 7.3), and δ 8.31 (br d, 1H, J=7.2 Hz). 13C NMR (75 MHz, CDCl3 /TMS): 13.59, 17.54, 47.31, 61.02, 61.48, and 172.17. [α]25D =-4.1°±0.4° (c=1.99, CHCl3). HRMS: calcd for C7H14NO4 (M+H)+, 176.0923; found, 176.0921.

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