Phosphorus oxychloride → 7-Chlorothieno[3,2-b]pyridine-6-carbonitrile
Reaction equation
O=[C:2]1[C:7]([C:8]#[N:9])=[CH:6][NH:5][C:4]2[CH:10]=[CH:11][S:12][C:3]1=2.P(Cl)(Cl)([Cl:15])=O>>[Cl:15][C:2]1[C:7]([C:8]#[N:9])=[CH:6][N:5]=[C:4]2[CH:10]=[CH:11][S:12][C:3]=12Participants
Procedure
A mixture of 7-oxo-4,7-dihydrothieno[3,2-b]pyridine-6-carbonitrile (3.00 g, 17.0 mmol) and 25 mL of phosphorous oxychloride is heated at reflux for 10 minutes. The reaction mixture is cooled to room temperature and the dark solids are removed by filtration. The filtrate is poured into hexane and allowed to stand at room temperature. The solvent is decanted off and the residual oil is dissolved in ethyl acetate and the solution is washed with water. The organic layer is dried over magnesium sulfate, filtered and passed through silica gel. The filtrate is concentrated in vacuo to give 770 mg of the desired product as a dark orange solid. A portion of this material is purified by flash column chromatography eluting with 1:1 ethyl acetate:hexane to provide 7-chlorothieno[3,2-b]pyridine-6-carbonitrile as tan crystals, mp 110–111° C.; 1H NMR (DMSO-d6) δ 7.81 (d, J=5 Hz, 1H), 8.59 (d, J=5 Hz, 1H), 9.12 (s, 1H); MS 194.9 (M+H)+.
Workup
- temperatureis heated
- temperatureat reflux for 10 minutes
- customthe dark solids are removed by filtration
- additionThe filtrate is poured into hexane
- customto stand at room temperature
- customThe solvent is decanted off
- dissolutionthe residual oil is dissolved in ethyl acetate
- washthe solution is washed with water
- dry with materialThe organic layer is dried over magnesium sulfate
- filtrationfiltered
- concentrationThe filtrate is concentrated in vacuo
Sources & evidence
- ORD record
- ord-bc665d7aa590435fac38454f9d5520bd
- Source dataset
- uspto-grants-2007_10
- Patent number
- US07276519B2
Reaction notes
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