Hydrochloric Acid → 6-Iodo-2-phenylpyrazolo[1,5-a]pyridine-3-carboxylic acid

HRID 44021

Reaction equation

C[O:2][C:3]([C:5]1[C:6]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)=[N:7][N:8]2[CH:13]=[C:12]([I:14])[CH:11]=[CH:10][C:9]=12)=[O:4].CO.O1CCCC1.Cl>[Li+].[OH-].O.C(OC(=O)C)C>[I:14][C:12]1[CH:11]=[CH:10][C:9]2[N:8]([N:7]=[C:6]([C:15]3[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=3)[C:5]=2[C:3]([OH:4])=[O:2])[CH:13]=1

Participants

Conditions

Temperature: 45 °C

Procedure

Methyl-6-iodo-2-phenylpyrazolo[1,5-a]pyridine-3-carboxylate (250 mg, 0.661 mmol) was dissolve in aqueous LiOH(2N,1 mL), methanol (2 mL) and tetrahydrofuran (7 mL). This solution was stirred overnight at 45° C. After 24 hours, 2 mL 2M LiOH and 2 mL methanol were added. Heated at 55° C. overnight. The reaction was cooled on an ice water bath and aqueous hydrochloric acid (10 mL, 1N) was added dropwise until acidic by pH paper. Ethylacetate (200 mL) and water (40 mL) were added. The organic portion was extracted with brine (20 mL) and was dried over magnesium sulfate. The solvent was removed by rotory evaporation. The residue was place under vacuum overnight to give of a white solid (204 mg, 85%). 1H NMR (500 MHz, DMSO-D6) δ ppm 7.47 (m, 3H) 7.77 (m, 2H) 7.97 (d, J=9.46 Hz, 1H) 9.27 (s, 1H).

Workup

waitAfter 24 hours
temperatureHeated at 55° C. overnight
temperatureThe reaction was cooled on an ice water bath
extractionThe organic portion was extracted with brine (20 mL)
dry with materialwas dried over magnesium sulfate
customThe solvent was removed by rotory evaporation
customunder vacuum overnight

Sources & evidence

ORD record: ord-ebd467546d364a949bbc9bec91c6b6a0
Source dataset: uspto-grants-2013_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08536338B2

Linked notes

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