Hydrochloric Acid → HCID 86652997, compound

To a solution of (2,6-difluorophenyl)-1H-pyrazol-5-amine (2.60 g, 13.3 mmol) in 8 mL of EtOAc and 4 mL of EtOH was added 8 mL of HCl in 2-propanol (5-6 N). The heterogeneous mixture was cooled with an ice-NaCl bath, and isopentyl nitrite (1.83 mL, 13.6 mmol) was added drop wise (within 10 min) to prevent the temperature from exceeding 10° C. After stirring for 15 min, the reaction mixture became homogeneous. Stirring was continued for a total of 40 min. The brown homogeneous solution was diluted with 150 mL of EtOAc, and neutralized with ammonium hydroxide. The EtOAc layer was separated and washed with brine to afford a rusty crystalline solid which was triturated with 15 mL Hexanes. The rusty solid was collected and dried in a vacuum oven at 45° C. for 2 h to afford 1-(2,6-difluorophenyl)-4-nitroso-1H-pyrazol-5-amine This crude material was used without further purification. MS (ES+): 225.1 (M+H)+.

1. temperatureThe heterogeneous mixture was cooled with an ice-NaCl bath
2. customfrom exceeding 10° C
3. stirringStirring
4. customwas continued for a total of 40 min
5. customThe EtOAc layer was separated
6. washwashed with brine
7. customto afford a rusty crystalline solid which
8. customwas triturated with 15 mL Hexanes
9. customThe rusty solid was collected
10. customdried in a vacuum oven at 45° C. for 2 h

ORD record

ord-77987d248d4a4a65a3bcfa96dfe2f524

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08367671B2