6-chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridine-4-carbaldehyde → 1-(6-chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridin-4-yl)ethanol

HRID 588135Notes

Reaction equation

[Cl:1][C:2]1[N:7]=[C:6]([CH:8]=[O:9])[C:5]2[C:10]([O:32][CH3:33])=[N:11][N:12]([C:13]([C:26]3[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=3)([C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=3)[C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)[C:4]=2[CH:3]=1.[CH3:34][Mg]Br>C1COCC1>[Cl:1][C:2]1[N:7]=[C:6]([CH:8]([OH:9])[CH3:34])[C:5]2[C:10]([O:32][CH3:33])=[N:11][N:12]([C:13]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)([C:20]3[CH:21]=[CH:22][CH:23]=[CH:24][CH:25]=3)[C:26]3[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=3)[C:4]=2[CH:3]=1

Participants

Conditions

Temperature: -78 °C

Procedure

Chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridine-4-carbaldehyde (Intermediate 11B, 535 mg, 1.2 mmol) was dissolved in THF (8 ml) cooled to −78° C. and charged with methylmagnesium bromide (3M, 0.786 ml, 2.357 mmol). The reaction was allowed to stir for 1 hr, eventually reaching 0° C. The reaction was slowly quenched with saturated ammonium chloride (3 mL) and partioned between EtOAc 2×10 mL, washed with brine, dried over MgSO4, filtered, and concentrated in vacuo. The residue was then loaded onto silica gel and purified by MPLC 0-25% EtOAc/hexanes to provide 1-(6-chloro-3-methoxy-1-trityl-1H-pyrazolo[4,3-c]pyridin-4-yl)ethanol (38B). MS: [M+H]+ m/z 470.

Workup

customeventually reaching 0° C
customThe reaction was slowly quenched with saturated ammonium chloride (3 mL)
washwashed with brine
dry with materialdried over MgSO4
filtrationfiltered
concentrationconcentrated in vacuo
custompurified by MPLC 0-25% EtOAc/hexanes

Sources & evidence

ORD record: ord-7713c218bae24f3980fd1a9a58259953
Source dataset: uspto-grants-2016_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09226922B2

Reaction notes

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