1-(2-Phenylpyrazolo[1,5-a]pyridin-3-yl)-1-ethanone → 4-Oxo-4-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)crotonic acid

HRID 703959Notes

Reaction equation

O.[C:2]([OH:6])(=[O:5])[CH:3]=O.[C:7]([C:10]1[C:11]([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)=[N:12][N:13]2[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=12)(=[O:9])[CH3:8]>C(Cl)Cl>[O:9]=[C:7]([C:10]1[C:11]([C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)=[N:12][N:13]2[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=12)/[CH:8]=[CH:3]/[C:2]([OH:6])=[O:5]

Participants

Conditions

Temperature: 100 °C

Procedure

A mixture of glyoxylic acid monohydrate (3.50 g) and 3-acetyl-2-phenylpyrazolo[1,5-a]pyridine (5.00 g) was stirred and heated at 100° C. for 4 hours. The warm reaction mixture was dissolved in methylene chloride (50 ml), and then extracted with 1N aqueous solution of sodium hydroxide (50 ml). The aqueous layer was washed with methylene chloride (total 200 ml) and then with ethyl acetate (total 200 ml). The aqueous solution was adjusted to pH 4~5 with 10% hydrochloric acid. The isolated oil was extracted with chloroform. The extract was evaporated in vacuo and crystallized from methylene chloride to give 4-oxo-4-(2phenylpyrazolo[1,5-a]pyridin-3-yl)crotonic acid (0.46 g).

Workup

customThe warm reaction mixture
extractionextracted with 1N aqueous solution of sodium hydroxide (50 ml)
washThe aqueous layer was washed with methylene chloride (total 200 ml)
extractionThe isolated oil was extracted with chloroform
customThe extract was evaporated in vacuo
customcrystallized from methylene chloride

Sources & evidence

ORD record: ord-442bb8c4a2a5411882dbee5275f16d7e
Source dataset: uspto-grants-1991_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04985444

Reaction notes

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