N-bromobutanimide → 7-Bromo-2-(4-fluorophenyl)-3-pyridin-4-ylpyrazolo[1,5-a]pyridine

HRID 1373834Notes

Reaction equation

[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:16]([C:17]3[CH:22]=[CH:21][N:20]=[CH:19][CH:18]=3)=[C:11]3[CH:12]=[CH:13][CH:14]=[CH:15][N:10]3[N:9]=2)=[CH:4][CH:3]=1.C([Li])CCC.[Br:28]N1C(=O)CCC1=O>O1CCCC1.CCOCC>[Br:28][C:15]1[N:10]2[N:9]=[C:8]([C:5]3[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=3)[C:16]([C:17]3[CH:18]=[CH:19][N:20]=[CH:21][CH:22]=3)=[C:11]2[CH:12]=[CH:13][CH:14]=1

Participants

Conditions

Temperature: -78 °C

Procedure

To a stirred solution of of 2-(4-fluorophenyl)-3-(4-pyridyl)-pyrazolo[1,5-α]pyridine (100 mg, 0.346 mmol) in 4 ml of tetrahydrofuran at −78° C. under N2 was added 2.5 M n-butyllithium in hexanes (2 eq.). The mixture was stirred at −78° C. for 30 min and N-bromosuccinimide (2.2 eq.) was then added. The mixture was allowed to warm to room temperature after 30 min and was stirred at room temperature for 1 hr. The mixture was diluted with ether and washed with 1N hydrochloric acid solution. The aqueous layer was basified with 1N sodium hydroxide solution and extracted thoroughly with ether. The combined organic layers were dried on anhydrous magnesium sulfate, filtered and evaporated. Purification by chromatography yielded 7-bromo-2-(4-fluorophenyl)-3-pyridin-4-ylpyrazolo[1,5-α]pyridine as a yellow solid. 1H NMR (CDCl3): δ 8.65 (d, 2H, J=5.0 Hz), 7.56–7.68 (m, 3H), 7.31 (d, 2H, J=5.0 Hz), 7.11–7.30 (m, 4H; MS m/z 368 (M+1).

Workup

temperatureto warm to room temperature after 30 min
stirringwas stirred at room temperature for 1 hr
washwashed with 1N hydrochloric acid solution
extractionextracted thoroughly with ether
dry with materialThe combined organic layers were dried on anhydrous magnesium sulfate
filtrationfiltered
customevaporated
customPurification by chromatography

Sources & evidence

ORD record: ord-d62f8b9d951a499591135296a0f4a423
Source dataset: uspto-grants-2007_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07163940B2

Reaction notes

Loading…