反应详情

To a solution of 5-bromo-pyridine-2-carboxylic acid methyl ester (1.0 eq.) (see Synth. Commun., 1997, 27, 515) in THF:MeOH (2:1; 0.2M) was added aqueous LiOH (1M; 3.0 eq.). The mixture was stirred for 12 h, concentrated and dried under vacuum. The residue was diluted in CH2Cl2 (0.2M), oxalyl chloride (8.0 eq.) was added and the mixture was stirred for 3h, concentrated, dried under vacuum and diluted in CH2Cl2 (0.2M). Cyclopropylamine (10 eq.) was added and the mixture was stirred for 2 h, poured in saturated aqueous NaHCO3 and extracted with EtOAc (2×). The combined organic extracts were washed with brine, dried over Na2SO4, filtered and concentrated. Flash chromatography (CH2Cl2:EtOAc; 9:1) afforded the title compound as a yellow solid.

1. concentrationconcentrated
2. customdried under vacuum
3. additionThe residue was diluted in CH2Cl2 (0.2M)
4. concentrationconcentrated
5. customdried under vacuum
6. additiondiluted in CH2Cl2 (0.2M)
7. stirringthe mixture was stirred for 2 h
8. extractionextracted with EtOAc (2×)
9. washThe combined organic extracts were washed with brine
10. dry with materialdried over Na2SO4
11. filtrationfiltered
12. concentrationconcentrated