4,5,6,7-Tetrahydro-(1,2,3)oxadiazolo(3,4-a)pyridin-8-ium-3-olate → 2-(4-Fluorophenyl)-3-(pyridin-4-yl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine

HRID 1890251Notes

Reaction equation

[N:1]1OC([O-])=[C:4]2[CH2:9][CH2:8][CH2:7][CH2:6][N+:5]=12.[F:11][C:12]1[CH:17]=[CH:16][C:15]([C:18]#[C:19][C:20]2[CH:25]=[CH:24][N:23]=[CH:22][CH:21]=2)=[CH:14][CH:13]=1>C1(C)C=C(C)C=C(C)C=1>[F:11][C:12]1[CH:13]=[CH:14][C:15]([C:18]2[C:19]([C:20]3[CH:21]=[CH:22][N:23]=[CH:24][CH:25]=3)=[C:4]3[CH2:9][CH2:8][CH2:7][CH2:6][N:5]3[N:1]=2)=[CH:16][CH:17]=1

Participants

Conditions

Temperature: 165 °C

Procedure

A mixture of 1.64 g (11.1 mmol) of 4,5,6,7-tetrahydro[1,2,3]oxadiazolo[3,4-a]pyridin-8-ium 3-olate and 2.19 g (11.1 mmol) of 4-{[4-fluorophenyl]ethynyl}pyridine in 40 ml of mesitylene is stirred under argon at 165° C. for 16 h. After cooling, the reaction mixture is concentrated under reduced pressure. Purification by column chromatography on silica gel (cyclohexane/ethyl acetate) gives 888 mg (27%) of the desired product; log P(HCOOH): 1.03; 1H-NMR (CDCl3-d1): 8.52 (d, 2H), 7.38 (dd, 2H), 7.08 (d, 2H), 7.00 (dd, 2H), 4.25 (dd, 2H), 2.85 (dd, 2H), 2.12 (m, 2H), 1.92 (m, 2H).

Workup

temperatureAfter cooling
concentrationthe reaction mixture is concentrated under reduced pressure
customPurification by column chromatography on silica gel (cyclohexane/ethyl acetate)

Sources & evidence

ORD record: ord-89180eb0c441414ebd9680adf52cba8d
Source dataset: uspto-grants-2013_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08507472B2

Reaction notes

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