1-Ethynyl-4-fluorobenzene → 2-(4-Fluorophenyl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine

HRID 1890256Notes

Reaction equation

HRID 1890256 reaction equation
[N:1]1O[C:3]([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)=[CH:14][CH:13]=1>C1(C)C=C(C)C=C(C)C=1>[F:11][C:12]1[CH:17]=[CH:16][C:15]([C:18]2[CH:3]=[C:4]3[CH2:9][CH2:8][CH2:7][CH2:6][N:5]3[N:1]=2)=[CH:14][CH:13]=1

Participants

4

Reactant 2

HCID 5226271-Ethynyl-4-fluorobenzeneHCID 118450904,5,6,7-Tetrahydro-(1,2,3)oxadiazolo(3,4-a)pyridin-8-ium-3-olate

Product 1

HCID 674383212-(4-Fluorophenyl)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyridineYield 27%

Reagents, catalysts & solvents 1

HCID 7947MesityleneSolvent

Conditions

Temperature
165 °C

Procedure

A mixture of 2.44 g (16.5 mmol) of 4,5,6,7-tetrahydro[1,2,3]oxadiazolo[3,4-a]pyridin-8-ium 3-olate and 2.15 g (16.5 mmol) of 4-fluorophenylacetylene in 80 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): 2.76; 1H-NMR (MeCN-d3): 7.76 (dd, 2H), 7.11 (dd, 2H), 6.29 (s, 1H), 4.09 (dd, 2H), 2.79 (dd, 2H), 2.02 (m, 2H), 1.84 (m, 2H).

Workup

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

Sources & evidence

ORD record
ord-caf551ea99aa4aeb8f6b04a51bf1494b
Source dataset
uspto-grants-2013_08
Patent number
US08507472B2

Reaction notes

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