Phosphorus oxychloride → Ethyl 4-chloro-1-(4-methoxybenzyl)-1H-pyrazolo[3,4-b]pyridine-5-carboxylate

HRID 1499480Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:24]=[CH:23][C:6]([CH2:7][N:8]2[C:12]3[NH:13][CH:14]=[C:15]([C:18]([O:20][CH2:21][CH3:22])=[O:19])[C:16](=O)[C:11]=3[CH:10]=[N:9]2)=[CH:5][CH:4]=1.O=P(Cl)(Cl)[Cl:27]>ClCCCl>[Cl:27][C:16]1[C:15]([C:18]([O:20][CH2:21][CH3:22])=[O:19])=[CH:14][N:13]=[C:12]2[N:8]([CH2:7][C:6]3[CH:23]=[CH:24][C:3]([O:2][CH3:1])=[CH:4][CH:5]=3)[N:9]=[CH:10][C:11]=12

Participants

Conditions

Temperature: 90 °C

Procedure

To a solution of ethyl 1-(4-methoxybenzyl)-4-oxo-4,7-dihydro-1H-pyrazolo[3,4-b]pyridine-5-carboxylate (4.0 g, 13 mmol) in 1,2-dichloroethane (9.8 mL) was added POCl3 (2.4 mL, 26 mmol). The resulting mixture was heated at 90° C. for 3 h. After cooling, the most volatile were removed by vacuum, and the residue was diluted with EtOAc and washed with aq. Na2CO3 solution. The organic layer was washed water and brine, dried and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel using CombiFlash® apparatus, eluting with 10 to 60% EtOAc in hexanes, to give the sub-title compound (3.9 g, 95%). LCMS calc. for C17H17ClN3O3 (M+H)+: m/z=346.1. Found: 346.1.

Workup

temperatureAfter cooling
customthe most volatile were removed by vacuum
additionthe residue was diluted with EtOAc
washwashed with aq. Na2CO3 solution
washThe organic layer was washed water and brine
customdried
concentrationconcentrated under reduced pressure
customThe residue was purified by column chromatography on silica gel using CombiFlash® apparatus
washeluting with 10 to 60% EtOAc in hexanes

Sources & evidence

ORD record: ord-48d36b036dc54d5f9c69eabb2b17f286
Source dataset: uspto-grants-2015_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09200004B2

Reaction notes

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