Ammonium Chloride → 4-Chloro-3,6-dimethoxypyridazine

温度

0 °C

A solution of n-butyllithium (1.6 M in hexanes, 2.45 mL, 3.92 mmol) was added to a cold solution of THF (20 mL) at −78° C. Tetramethylpiperidine (0.67 mL, 3.92 mol) was introduced and the solution was warmed to 0° C. and kept at this temperature for 20 min; it was then cooled to −78° C. A solution of 3,6-dimethoxy-pyridazine (500 mg, 3.57 mmol) in THF (5 mL) was added slowly and the mixture was stirred at −78° C. for 45 min. This reaction mixture was transferred to a solution of achloroethane (1.268 g, 5.36 mmol) in THF (10 mL) at −78° C. 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 10-20% EtOAc in hexanes to afford, after evaporation, the title compound as a white solid (372 mg, 60%): 1H NMR (400 MHz, DMSO) δ 7.04 (s, 1H), 4.11 (s, 3H), 4.04 (s, 3H); LCMS (+ESI, M+H+) m/z 175.

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

ORDレコード

ord-07e52b6e7d684b24b80b87a23e8dd7dd

出典データセット

uspto-grants-2007_12

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07312215B2