反应详情

温度

-78 °C

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), a solution of 5-(3-nitro-pyrazol-1-ylmethyl)-furan-2-carboxylic acid methyl ester (25.40 g, 61.31 mmol) in THF (154.0 mL) was treated dropwise, at −78° C. with DiBAL (165.0 mL of a 1.7M solution in toluene, 245.22 mmol). The reaction mixture was stirred at −78° C. for 1 h and then allowed to warm up to rt. Sat. aq. Rochelle's salt (600 mL) was added and the reaction mixture was stirred at rt for 2 h. The aq. layer was extracted with EA (2×500 mL) and the combined org. extracts were dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (40:60 hept-EA) gave the title compound. TLC: rf (40:60 hept-EA)=0.28. LC-MS-conditions 02: tR=0.75 min. 1H NMR (400 MHz, CDCl3) δ 2.05 (s, 1H), 4.60 (s, 2H), 5.36 (s, 2H), 6.31 (d, J=3.0 Hz, 1H), 6.46 (d, J=3.0 Hz, 1H), 6.91 (d, J=2.5 Hz, 1H), 7.51 (d, J=2.5 Hz, 1H).

1. temperatureto warm up to rt
2. stirringthe reaction mixture was stirred at rt for 2 h
3. extractionThe aq. layer was extracted with EA (2×500 mL)
4. dry with materialextracts were dried over MgSO4
5. filtrationfiltered
6. customthe solvents were removed under reduced pressure
7. customPurification of the residue by FC (40:60 hept-EA)