Nitric Acid → HCID 178418805, compound

Temperature

0 °C

Sulfuric acid (95-98%, 250 mL) is placed in a 1 L 4-neck round bottomed flask equipped with mechanical stirrer, thermometer and cooled to 0° C. 4-Phenylimidazole (87.2 g, 0.606 mol) is added in portions to keep the temperature under 10° C. The starting material is dissolved completely after stirring for 20 minutes. The mixture is cooled to 0° C., fuming nitric acid (28.42 mL, 0.606 mol) is added dropwise to keep the temperature at 0-5° C. The addition took about 1.5 h. After stirring at 0° C. for 1 h, the reaction mixture is poured into ice (3 Kg) and stirred for 20 minutes, neutralized with sodium hydroxide (340 g) and then sodium carbonate (10%) to pH˜10. The mixture is filtered; the solid is washed with water (3×500 mL), methanol (500 mL) and air-dried. The crude product is recrystallized with ethanol (20 mL/g) to give 50.5 g product as tan crystals. The mother liquor is concentrated and the residue is recrystallized with ethanol to give another crop of the product (11.2 g) with a total yield of 61.7 g (53.9%); mp 226-228° C.

1. customequipped with mechanical stirrer
2. customunder 10° C
3. dissolutionThe starting material is dissolved completely
4. temperatureThe mixture is cooled to 0° C.
5. customat 0-5° C
6. additionThe addition
7. waittook about 1.5 h
8. stirringAfter stirring at 0° C. for 1 h
9. stirringstirred for 20 minutes
10. filtrationThe mixture is filtered
11. washthe solid is washed with water (3×500 mL), methanol (500 mL)
12. customair-dried
13. customThe crude product is recrystallized with ethanol (20 mL/g)

ORD record

ord-d0987f5cc1a24ade975e6f90ed4d7fe1

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07713994B2