Ethyl formate → 5-Chloro-3,6-dimethoxy-pyridazine-4-carbaldehyde

온도

0 °C

A solution of n-butyllithium (1.6 M in hexanes, 0.39 mL, 0.63 mmol) was added to a cold solution of THF (10 mL) at −78° C. Tetramethylpiperidine (0.11 L, 0.63 mmol) was introduced and the solution was warmed to 0° C. and kept at this temperature for 20 min; it is then cooled to −78° C. A solution of 4-chloro-3,6-dimethoxy-pyridazine (100 mg, 0.57 mmol) in 20 THF (5 mL) was added slowly and the mixture was stirred at −78° C. After stirring for 45 min at −78° C., ethyl formate (0.07 mL, 0.86 mmol) was added and stirring was continued at −78° C. for 15 min. Saturated aqueous NH4Cl was added and the mixture was warmed to room temperature. The mixture was extracted with EtOAc, dried over MgSO4, and concentrated in vacuo to give the crude product, which was purified by flash chromatography, eluting with 20-30% EtOAc in hexanes to afford, after evaporation, the title compound as a light yellow solid (51 mg, 44%): IR (KBr, cm−1) 1702, 1474, 1388, 1022; 1H NMR (400 MHz, DMSO) δ 10.36 (s, 1H), 4.17 (s, 3H), 4.16 (s, 3H); LCMS (+ESI, M+H+) m/z 203.

1. temperatureit is then cooled to −78° C
2. stirringAfter stirring for 45 min at −78° C.
3. stirringstirring
4. waitwas continued at −78° C. for 15 min
5. temperaturethe mixture was warmed to room temperature
6. extractionThe mixture was extracted with EtOAc
7. dry with materialdried over MgSO4
8. concentrationconcentrated in vacuo

ORD 기록

ord-a632194c2d4248fdbfc6364b2ffb914a

출처 데이터셋

uspto-grants-2007_12

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US07312215B2