反应详情

To solution of Fmoc-β-Ala-OH (1.0 g, 3.212 mmol) and oxalyl chloride (0.428 g, 0.29 mL, 3.373 mmol) in dichloromethane (20.0 mL) was added a few drops of N,N-dimethylformamide at 0° C. The mixture was stirred at room temperature for 1 hr followed by addition of cyclopropylmethylamine (0.229 g, 0.28 mL, 3.212 mmol) and triethylamine (0.65 g, 0.90 mL, 6.424 mmol). After 10 min, the mixture was treated with 1 M hydrochloride (10.0 mL) and the aqueous mixture was extracted with dichloromethane (3×30.0 mL). The organic solution was concentrated in vacuo to dryness. The residue was treated with a solution of 20% piperidine in N,N-dimethylforamide (20.0 mL) for 0.5 hr. After removal of the solvent in vacuo, the residue was treated with 1 M hydrochloride (20.0 mL) and ethyl acetate (20.0 mL). The mixture was separated and the aqueous layer was basified with solid sodium hydroxide to pH=8. The precipitate was removed by filtration and the aqueous solution was subjected to ion exchange column eluted with 20% pyridine to give 0.262 g (57%) of N-cyclopropylmethyl β-alanine amide. 1H NMR (200 MHz, CD3OD) δ 0.22 (m, 2H), 0.49 (m, 2H), 0.96 (m, 2H), 2.40 (t, 2H), 2.92 (t, 2H), 3.05 (d, 2H); MS (ES): 143.1 (M++1).

1. waitAfter 10 min
2. extractionthe aqueous mixture was extracted with dichloromethane (3×30.0 mL)
3. concentrationThe organic solution was concentrated in vacuo to dryness
4. additionThe residue was treated with a solution of 20% piperidine in N,N-dimethylforamide (20.0 mL) for 0.5 hr
5. customAfter removal of the solvent in vacuo
6. additionthe residue was treated with 1 M hydrochloride (20.0 mL) and ethyl acetate (20.0 mL)
7. customThe mixture was separated
8. customThe precipitate was removed by filtration
9. washeluted with 20% pyridine