Ammonium → 2-Methyl-2H-indazole-4-carbaldehyde

Under nitrogen atmosphere, dimethyl sulfoxide (70.0 mL, 987 mmol) was added to a solution of oxalyl chloride (43.2 mL, 493 mmol) in dichloromethane (2.47 L) at −78° C., and the mixture was stirred for 2 hr. To the reaction mixture was added (2-methyl-2H-indazol-4-yl)methanol (40.0 g, 247 mmol), and the mixture was stirred for 1 hr. To the reaction mixture was added triethylamine (139 mL, 987 mmol) at −78° C., and the mixture was stirred for 1 hr and warmed to room temperature over 4 hr. To the reaction mixture was added aqueous ammonium is chloride solution, and the mixture was extracted with dichloromethane. The extract was washed with saturated brine, and dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by recrystallization (dichloromethane/hexane) to give the title compound (36.3 g, yield 92%).

1. stirringthe mixture was stirred for 1 hr
2. stirringthe mixture was stirred for 1 hr
3. extractionthe mixture was extracted with dichloromethane
4. washThe extract was washed with saturated brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customthe solvent was evaporated under reduced pressure
7. customThe residue was purified by recrystallization (dichloromethane/hexane)

ORD record

ord-4f52eaa428214f52970c5ea8a9b9e7f3

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08110585B2