Methyl 4-acetylbenzoate → methyl 4-[1-hydroxy-1-(1-trityl-1H-pyrazol-4-yl)ethyl]benzoate

HRID 595298Notes

Reaction equation

[Li]CCCC.Br[C:7]1[CH:8]=[N:9][N:10]([C:12]([C:25]2[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=2)([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:11]=1.[C:31]([C:34]1[CH:43]=[CH:42][C:37]([C:38]([O:40][CH3:41])=[O:39])=[CH:36][CH:35]=1)(=[O:33])[CH3:32]>C1COCC1>[OH:33][C:31]([C:34]1[CH:43]=[CH:42][C:37]([C:38]([O:40][CH3:41])=[O:39])=[CH:36][CH:35]=1)([C:7]1[CH:8]=[N:9][N:10]([C:12]([C:25]2[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=2)([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:11]=1)[CH3:32]

Participants

Conditions

Temperature: -78 °C

Procedure

n-BuLi (1.65 mL, 4 mmol) was added dropwise to a mixture of 4-bromo-1-trityl-1H-pyrazole (1.5 g, 3.8 mmol) in THF (15 mL) cooled to −78° C. Then the mixture was stirred at −78° C. for 1 hour. After methyl 4-acetylbenzoate (0.71 g, 3.8 mmol) in THF (1 mL) was added, the mixture was stirred at −78° C. for 2 hours, and then quenched with saturated aqueous ammonium chloride solution. The mixture was extracted with ethyl acetate. The organic layer was concentrated and the residue was purified by chromatography on silica gel to afford methyl 4-[1-hydroxy-1-(1-trityl-1H-pyrazol-4-yl)ethyl]benzoate. MS ESI calc'd. for C32H29N2O3 [M+H]+ 489. found 489.

Workup

stirringthe mixture was stirred at −78° C. for 2 hours
customquenched with saturated aqueous ammonium chloride solution
extractionThe mixture was extracted with ethyl acetate
concentrationThe organic layer was concentrated
customthe residue was purified by chromatography on silica gel

Sources & evidence

ORD record: ord-d56f52b979d54fcdaac4de9e075b4f75
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09242984B2

Reaction notes

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