Pyridine → HCID 58506460, compound

HRID 2167301Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:8]=[C:7]([O:9][CH3:10])[CH:6]=[CH:5][C:4]=1B(O)O.[NH:14]1[CH:18]=[CH:17][C:16]([C:19]([O:21][CH3:22])=[O:20])=[N:15]1.N1C=CC=CC=1>CN(C=O)C.CC([O-])=O.CC([O-])=O.[Cu+2]>[CH3:1][O:2][C:3]1[CH:8]=[C:7]([O:9][CH3:10])[CH:6]=[CH:5][C:4]=1[N:14]1[CH:18]=[CH:17][C:16]([C:19]([O:21][CH3:22])=[O:20])=[N:15]1

Participants

Conditions

Temperature: 90 °C

Procedure

To a solution of 2,4-dimethoxyphenylboronic acid 1 (2.88 g, 15.8 mmol, 1.00 equiv) in DMF (100 mL) was added methyl 1H-pyrazole-3-carboxylate (3.00 g, 23.7 mmol, 1.50 equiv), Cu(OAc)2 (5.70 g, 31.6 mmol, 2.00 equiv), and pyridine (3.76 g, 47.4 mmol, 3 equiv). The resulting solution was stirred for 2 h at 90° C. The solids were filtrated off by filtration and the filtrate was extracted by EtOAc (200 mL×3). The combined organic layers were dried by anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column and eluted with PE/EA (3/1). This resulted in 1.5 g (36%) of methyl 1-(2,4-dimethoxyphenyl)-1H-pyrazole-3-carboxylate 2 as a brown solid. 1H NMR (300 MHz, CDCl3): δ 7.88 (d, J=2.4 Hz, 1H), 7.61 (d, J=9 Hz, 1H), 6.97 (d, J=2.4 Hz, 1H), 6.59 (s, 1H), 7.73, 6.58 (d, J=8.7 Hz, 1H). LC-MS: m/z=263 (MH)+.

Workup

filtrationThe solids were filtrated off by filtration
extractionthe filtrate was extracted by EtOAc (200 mL×3)
dry with materialThe combined organic layers were dried by anhydrous sodium sulfate
concentrationconcentrated under vacuum
washeluted with PE/EA (3/1)
customThis resulted in 1.5 g (36%) of methyl 1-(2,4-dimethoxyphenyl)-1H-pyrazole-3-carboxylate 2 as a brown solid

Sources & evidence

ORD record: ord-f944df4a06094c59b3ad5ef9c948dfe5
Source dataset: uspto-grants-2015_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09045440B2

Reaction notes

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