Ammonium Chloride → 1-(4-Amino-5-chloro-1H-pyrazol-1-yl)-2-methylpropan-2-ol

To a solution of 5-chloro-1-(2-methyl-2-((trimethylsilyl)oxy)propyl)-4-nitro-1H-pyrazole (1 equiv) in EtOH (0.13 M) was added iron powder (5.2 equiv) and ammonium chloride (14.3 equiv). The mixture was heated to reflux for 24 h and then filtered through celite. The filtrate was concentrated and dissolved in ethyl acetate. The organic solution was washed with aqueous sodium bicarbonate and brine, dried over sodium sulfate, filtered and concentrated. The product was purified by reverse phase silica gel chromatography (5-95% acetonitrile in water) to afford the title compound as an oil (90% yield). 1H NMR (400 MHz, CHLOROFORM-d1) δ ppm 7.27 (s, 1H), 4.06 (s, 1H), 3.99 (s, 2H), 2.95 (bs, 2H), 1.67 (s, 1H), 1.77 (s, 6H). MS (ESI) m/z 190.1 [M+H]+.

1. temperatureThe mixture was heated
2. temperatureto reflux for 24 h
3. filtrationfiltered through celite
4. concentrationThe filtrate was concentrated
5. dissolutiondissolved in ethyl acetate
6. washThe organic solution was washed with aqueous sodium bicarbonate and brine
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe product was purified by reverse phase silica gel chromatography (5-95% acetonitrile in water)

ORD record

ord-e662bd38cde04f09899bcfaca34f66db

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09428509B2