Aluminium lithium hydride → HCID 178519885, compound

Ethyl 3-(trifluoromethyl)-1H-pyrazole-4-carboxylate (95.00 g, 0.456 mol) was dissolved in dry THF (1 L) and the resulting solution cooled in an acetone/ice bath. A 1M solution of LiAlH4 in THF (550 mL, 0.550 mol) was added over 30 min, keeping the temperature <10° C. Cooling was then removed and the reaction mixture was stirred at RT for 4 h. The reaction was again cooled and a 1:1 THF:water solution (250 mL) was added with cooling (maintaining the temperature <20° C.), followed by 5M HCl (160 mL) to neutrality/pH 6. EtOAc (1.5 L) was added and the mixture stirred for 30 min then left to settle overnight. The resulting grey granular solid was removed by filtration through dicalite and washed with EtOAc. The combined filtrates were washed with brine and dried over MgSO4, before concentrating in vacuo to give a white solid (76.00 g, 0.457 mol, 100%).

1. temperaturethe resulting solution cooled in an acetone/ice bath
2. customthe temperature <10° C
3. temperatureCooling
4. customwas then removed
5. temperatureThe reaction was again cooled
6. additiona 1:1 THF:water solution (250 mL) was added
7. temperaturewith cooling (
8. temperaturemaintaining the temperature <20° C.),
9. additionEtOAc (1.5 L) was added
10. stirringthe mixture stirred for 30 min
11. waitthen left
12. waitto settle overnight
13. customThe resulting grey granular solid was removed by filtration through dicalite
14. washwashed with EtOAc
15. washThe combined filtrates were washed with brine
16. dry with materialdried over MgSO4
17. concentrationbefore concentrating in vacuo

ORD record

ord-6bdbb48b2fba44da9a829fa48a561bf2

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08129397B2