Hydrochloric Acid → 3'-Bromo-5'-(trifluoromethyl)acetophenone

Temperatur

0 °C

A flask was charged with water (42 ml), cooled to 0° C., and treated with concentrated hydrochloric acid (21.7 ml) and sulfuric acid (5.66 ml). To this was added 3-amino-5-bromobenzotrifluoride (8.77 ml, 62.5 mmol). The reaction was treated with a solution of sodium nitrite (5.39 g, 78 mmol) in water (10 mL). The resulting reaction mixture was stirred for 30 min at 0° C. The reaction was transferred to a solution of acetaldoxime (5.71 ml, 94 mmol) and copper(II) sulfate (0.499 g, 3.12 mmol) in water (30 mL) at room temperature. After stirring for 1 h at room temperature, the reaction was heated to reflux and held there for 3 h. The reaction was cooled and diluted with pentane. It gave an intractable suspension. The reaction mixture was filtered through a sintered glass funnel. The layers were separated. The organics were washed with water, then brine, dried over magnesium sulfate, and concentrated. The crude residue was distilled (high vacuum, 75° C.) to give 3 fractions of varying levels of purity. Total yield was 8.5 g (51%) with purity that ranged from 10:1 to 1:1. 1H NMR (500 MHz, CDCl3) δ ppm 8.25 (s, 1H), 8.11 (s, 1H), 7.95 (s, 1H), 2.63 (s, 3H).

1. customThe resulting reaction mixture
2. stirringAfter stirring for 1 h at room temperature
3. temperaturethe reaction was heated
4. temperatureto reflux
5. waitheld there for 3 h
6. temperatureThe reaction was cooled
7. customIt gave an intractable suspension
8. filtrationThe reaction mixture was filtered through a sintered glass funnel
9. customThe layers were separated
10. washThe organics were washed with water
11. dry with materialbrine, dried over magnesium sulfate
12. concentrationconcentrated
13. distillationThe crude residue was distilled (high vacuum, 75° C.)
14. customto give 3 fractions of varying levels of purity

ORD-Eintrag

ord-90327fc22da147d785d910887f5fef09

Quelldatensatz

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08383821B2