Cyclopropylamine → 5-bromo-2-cyclopropyl-3-methyl-2H-indazole

温度

60 °C

To a solution of 1-(5-bromo-2-nitrophenyl)ethanone (4.0 g) in toluene (41 ml) were added cyclopropylamine (2.3 ml) and titanium(IV) tetraisopropoxide (14.4 ml) at room temperature, and the mixture was stirred at 60° C. for 17 hr. The reaction mixture was concentrated, triethyl phosphite (8.4 ml) was added to the residue, and the mixture was stirred at 150° C. for 5 hr. The reaction mixture was cooled, and diluted with ethyl acetate, and 1 M aqueous sodium hydroxide solution was added. The resulting insoluble solid was filtered off, and the filtrate was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane/ethyl acetate) to give the title compound (2.6 g).

1. concentrationThe reaction mixture was concentrated
2. additiontriethyl phosphite (8.4 ml) was added to the residue
3. stirringthe mixture was stirred at 150° C. for 5 hr
4. temperatureThe reaction mixture was cooled
5. additiondiluted with ethyl acetate, and 1 M aqueous sodium hydroxide solution
6. additionwas added
7. filtrationThe resulting insoluble solid was filtered off
8. extractionthe filtrate was extracted with ethyl acetate
9. washThe organic layer was washed with saturated brine
10. dry with materialdried over anhydrous magnesium sulfate
11. concentrationconcentrated under reduced pressure
12. customThe obtained residue was purified by silica gel column chromatography (hexane/ethyl acetate)

ORDレコード

ord-46a50a44a84c4333a0ed71b0b4023bc6

出典データセット

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US09199963B2