Hydrochloric Acid → HCID 18008969, compound

3-fluoro-2-naphthylamine (1.38 g, 8.57 mmol, see Step 2, Example 3) was placed in 20 mL concentrate HCl. The slurry was stirred in ice bath. To it was added dropwise a chilled solution of sodium nitrite (0.71 g, 10.3 mmol) in 4 mL water. After completion, the mixture was stirred for 30 min in ice bath. A chilled solution of SnCl2.2H2O (4.9 g, 21.6 mmol) in 4 mL concentrate HCl was added dropwise. The mixture was stirred for 30 min. It was chilled and filtered with a Buchner funnel to collect the solid hydrazine. The solid was dried in vacuuo. It was then dissolved in 50 mL glacial acetic acid. To it was added 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione (2.18 g, 10.6 mmol). The mixture was refluxed for 2 hrs. The solvent was removed in vacuuo. The residue was taken into DCM. It was washed with water ×2, dried, concentrated and subjected to flash column to isolate 3-trifluoromethyl-1-(3-fluoro-2-naphthyl)-5-(2-furyl)-1H-pyrazole (60%). Rf 0.52 (1:4 EtOAc:hexane). ES-MS: (M+H)+347.

1. concentrationconcentrate HCl
2. stirringAfter completion, the mixture was stirred for 30 min in ice bath
3. additionwas added dropwise
4. stirringThe mixture was stirred for 30 min
5. temperatureIt was chilled
6. filtrationfiltered with a Buchner funnel
7. customto collect the solid hydrazine
8. customThe solid was dried in vacuuo
9. dissolutionIt was then dissolved in 50 mL glacial acetic acid
10. temperatureThe mixture was refluxed for 2 hrs
11. customThe solvent was removed in vacuuo
12. washIt was washed with water ×2
13. customdried
14. concentrationconcentrated

ORD record

ord-cc7a2e3a96e04cddbc5cd5e5ed8ae799

Source dataset

uspto-grants-2003_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06632815B2