Ammonium Chloride → 1-(3-Benzyloxy-2,2-difluoropropyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 2279881Notes

Reaction equation

[CH2:1]([O:8][CH2:9][C:10]([F:19])([F:18])[CH2:11][N:12]1[CH:16]=[C:15](I)[CH:14]=[N:13]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C([Mg]Cl)(C)C.CO[B:27]1[O:31][C:30]([CH3:33])([CH3:32])[C:29]([CH3:35])([CH3:34])[O:28]1.[Cl-].[NH4+]>C1COCC1>[CH2:1]([O:8][CH2:9][C:10]([F:19])([F:18])[CH2:11][N:12]1[CH:16]=[C:15]([B:27]2[O:31][C:30]([CH3:33])([CH3:32])[C:29]([CH3:35])([CH3:34])[O:28]2)[CH:14]=[N:13]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Conditions

Temperature: -40 °C

Procedure

A solution of 1-(3-benzyloxy-2,2-difluoropropyl)-4-iodo-1H-pyrazole (Compound 59F, 1.8 g, 4.7 mmol) in THF (40 mL) was cooled to −78° C., treated with iPrMgCl (4.75 mL, 9.5 mmol, 2M) and the temperature was raised to −40° C. After 20 min stirring at −40° C., reaction mixture was cooled to −78° C. and treated with 2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.091 mL, 0.56 mmol). The reaction mixture was allowed to warm to RT, treated with sat. aq. ammonium chloride (20 mL) and extracted with ethyl acetate (20 mL). The organic layer was dried over Na2SO4, filtered and concentrated to give 1.56 g (89%) of desired product as an oil. 1H NMR (500 MHz, CDCl3) δ 7.81 (s, 1H), 7.78 (s, 1H), 7.36-7.33 (m, 5H), 4.64-4.59 (m, 4H), 3.56 (t, J=12 Hz, 2H), 1.26 (s, 12H).

Workup

customreaction mixture
temperaturewas cooled to −78° C.
temperatureto warm to RT
extractionextracted with ethyl acetate (20 mL)
dry with materialThe organic layer was dried over Na2SO4
filtrationfiltered
concentrationconcentrated

Sources & evidence

ORD record: ord-e3e06df473414f14aed961aedc9c9837
Source dataset: uspto-grants-2015_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09133224B2

Reaction notes

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