Potassium Carbonate → 3-Ethynyl-7-trifluoromethyl-5-(4-trifluoromethyl-phenyl)-pyrazolo[1,5-a]pyrimidine

HRID 268979Notes

Reaction equation

[F:1][C:2]([F:29])([F:28])[C:3]1[N:8]2[N:9]=[CH:10][C:11]([C:12]#[C:13][Si](C)(C)C)=[C:7]2[N:6]=[C:5]([C:18]2[CH:23]=[CH:22][C:21]([C:24]([F:27])([F:26])[F:25])=[CH:20][CH:19]=2)[CH:4]=1.C([O-])([O-])=O.[K+].[K+]>C1COCC1.CO.CC(OC)(C)C>[C:12]([C:11]1[CH:10]=[N:9][N:8]2[C:3]([C:2]([F:1])([F:29])[F:28])=[CH:4][C:5]([C:18]3[CH:23]=[CH:22][C:21]([C:24]([F:27])([F:26])[F:25])=[CH:20][CH:19]=3)=[N:6][C:7]=12)#[CH:13]

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 7-trifluoromethyl-5-(4-trifluoromethyl-phenyl)-3-trimethylsilanylethynyl-pyrazolo[1,5-a]-pyrimidine (Example C.1 step 3a) (13.65 g, ca. 26 mmol) in THF (40 mL) and MeOH (100 mL) at 0° C. was added K2CO3 (362 mg, 10 mol %), and the mixture was stirred at 0° C. for 6 h. Diluted with TBME and ice water, separated phases, washed organic layer with brine, dried over Na2SO4. Removal of the solvent in vacuum left a dark brown solid, which was purified by silica gel column chromatography with heptane/EtOAc 9:1 followed by trituration with heptane to give the 3-ethynyl-7-trifluoromethyl-5-(4-trifluoromethyl-phenyl)-pyrazolo[-1,5-a]pyrimidine (7.90 g, 89%) as a yellow solid. MS (ISP) 356.0 [(M+H)+]; mp 138° C.

Workup

customat 0° C.
customseparated phases
washwashed organic layer with brine
dry with materialdried over Na2SO4
customRemoval of the solvent in vacuum
waitleft a dark brown solid, which
customwas purified by silica gel column chromatography with heptane/EtOAc 9:1

Sources & evidence

ORD record: ord-87fd016fcbce4ce7b241746f42ffbd56
Source dataset: uspto-grants-2008_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07446113B2

Reaction notes

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