Potassium Carbonate → HCID 58316720, compound

HRID 2042187Notes

Reaction equation

[N+](C1C=C([N+]([O-])=O)C=CC=1[O-])([O-])=O.[NH2:14][N+:15]1[CH:20]=[CH:19][CH:18]=[C:17]([Br:21])[CH:16]=1.[CH3:22][O:23][C:24](=[O:31])[C:25]#[C:26][C:27]([CH3:30])([CH3:29])[CH3:28].C([O-])([O-])=O.[K+].[K+]>CN(C=O)C>[CH3:22][O:23][C:24]([C:25]1[C:26]([C:27]([CH3:30])([CH3:29])[CH3:28])=[N:14][N:15]2[CH:16]=[C:17]([Br:21])[CH:18]=[CH:19][C:20]=12)=[O:31]

Participants

Conditions

Temperature: 25 °C

Procedure

To a solution of 1-amino-3-bromo-pyridinium 2,4-dinitro-phenolate (example 41, step 1) (1.98 g, 14.16 mmol) in DMF (20 ml) were added 4,4-dimethyl-pent-2-ynoic acid methyl ester (CAS 20607-85-6) (5 g, 14.16 mmol, 1 equiv.) and K2CO3 (3.9 g, 28.3 mmol, 2 equiv.) and stirred at 25° C. while purging air. DMF was completely evaporated, the residue dissolved in ethyl acetate and washed with water (100 ml). The organic extract was dried with sodium sulfate, filtered and evaporated to dryness. The resulting crude product along with the undesired regioisomer 4-bromo-2-tert-butyl-pyrazolo[1,5-a]pyridine-3-carboxylic acid methyl ester was purified by column chromatography. The desired 6-bromo-2-tert-butyl-pyrazolo[1,5-a]pyridine-3-carboxylic acid methyl ester (1.04 g, 24% yield) was obtained as a white solid, MS: m/e=312.2 (M+H+).

Workup

customwhile purging air
customDMF was completely evaporated
dissolutionthe residue dissolved in ethyl acetate
washwashed with water (100 ml)
extractionThe organic extract
dry with materialwas dried with sodium sulfate
filtrationfiltered
customevaporated to dryness
customThe resulting crude product along with the undesired regioisomer 4-bromo-2-tert-butyl-pyrazolo[1,5-a]pyridine-3-carboxylic acid methyl ester was purified by column chromatography

Sources & evidence

ORD record: ord-8fb8513bcc64443ca58c4387d950b912
Source dataset: uspto-grants-2013_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08586581B2

Reaction notes

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