反应详情

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 5-(4-amino-pyrazol-1-ylmethyl)-furan-2-carboxylic acid methyl ester (2.90 g, 13.10 mmol) in CH2Cl2 (58.0 mL) was treated with DIPEA (3.37 mL, 19.66 mmol) followed by 2-chlorobenzylchloroformate (2.69 mL, 17.04 mmol). The reaction mixture was stirred at rt for 4 h before being quenched with water (100 mL), extracted with CH2Cl2 (3×50 mL). The combined org. extracts were dried over MgSO4, filtered, and the solvent was removed under reduced pressure. Purification of the residue by FC (50:50 hept-EA) gave the title compound as a solid. TLC: rf (50:50 hept-EA)=0.22. LC-MS-conditions 02: tR=0.94 min; [M+H]+=390.37. 1H NMR (400 MHz, CDCl3) δ 3.89 (s, 3H), 5.29 (s, 2H), 5.31 (s, 2H), 6.39 (d, J=2.5 Hz, 1H), 6.75 (s, 1H), 7.12 (d, J=3.0 Hz, 1H), 7.23-7.31 (m, 2H), 7.38-7.42 (m, 1H), 7.43-7.46 (m, 2H), 7.75 (s, 1H).

1. custombefore being quenched with water (100 mL)
2. extractionextracted with CH2Cl2 (3×50 mL)
3. dry with materialextracts were dried over MgSO4
4. filtrationfiltered
5. customthe solvent was removed under reduced pressure
6. customPurification of the residue by FC (50:50 hept-EA)