Sodium hydride → 7-Iodo-2-(4-methoxybenzyl)-2H-pyrazolo[4,3-b]pyridine

HRID 1522599Notes

Reaction equation

[I:1][C:2]1[CH:7]=[CH:6][N:5]=[C:4]2[CH:8]=[N:9][NH:10][C:3]=12.[H-].[Na+].Cl[CH2:14][C:15]1[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][CH:16]=1.[Cl-].[NH4+]>CN(C=O)C>[I:1][C:2]1[CH:7]=[CH:6][N:5]=[C:4]2[CH:8]=[N:9][N:10]([CH2:14][C:15]3[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][CH:16]=3)[C:3]=12.[I:1][C:2]1[C:3]2[C:4](=[CH:8][N:9]([CH2:14][C:15]3[CH:20]=[CH:19][C:18]([O:21][CH3:22])=[CH:17][CH:16]=3)[N:10]=2)[N:5]=[CH:6][CH:7]=1

Participants

Conditions

Temperature: 0 °C

Procedure

7-Iodo-1H-pyrazolo[4,3-b]pyridine (0.77 g, 3.14 mmol) and sodium hydride (0.151 g, 3.77 mmol) were combined in DMF (31.4 ml) and stirred for 10 minutes and cooled to 0° C. 1-(Chloromethyl)-4-methoxybenzene (0.449 ml, 3.30 mmol) was added and the reaction was allowed to stir at room temperature for 1 hour. The reaction mixture was poured into ice water (200 mL) containing saturated ammonium chloride (50 mL) and extracted with ethyl acetate (2×50 mL). The organics were separated and dried over sodium sulfate, filtered, and absorbed onto silica gel. Column chromatography with hexanes/ethyl acetate (0-50%) gave the products 7-iodo-1-(4-methoxybenzyl)-1H-pyrazolo[4,3-b]pyridine and 7-iodo-2-(4-methoxybenzyl)-2H-pyrazolo[4,3-b]pyridine as a 6:4 mixture of isomers (0.9 g, 78%). MS [M+H] found 366.1.

Workup

stirringto stir at room temperature for 1 hour
extractionextracted with ethyl acetate (2×50 mL)
customThe organics were separated
dry with materialdried over sodium sulfate
filtrationfiltered
customabsorbed onto silica gel

Sources & evidence

ORD record: ord-6e4188e6ade64a66a9009b54a203b66f
Source dataset: uspto-grants-2015_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09073918B2

Reaction notes

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