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 466000Notes

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-(2-phenylpyrazolo[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-592bb0ef7a5e457aaa25905875922557
Source dataset: uspto-grants-1992_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05155114

Reaction notes

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