3,4-dihydro-2H-pyran → 5-(Bromomethyl)-1-(2-tetrahydropyranyl)indazole
Reaction equation
Br.[Br:2][CH2:3][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9][N:8]=[CH:7]2.[O:13]1[CH:18]=[CH:17][CH2:16][CH2:15][CH2:14]1>C1COCC1.C(Cl)Cl>[Br:2][CH2:3][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH:14]1[CH2:15][CH2:16][CH2:17][CH2:18][O:13]1)[N:8]=[CH:7]2Participants
Procedure
A yellow suspension of 5-(bromomethyl)-1H-indazole hydrogen bromide (compound 92, 3.0 g, 14 mmol) and 3,4-dihydro-2H-pyran (Aldrich, 2.4 g, 29 mmol) in THF (100 mL) was heated at reflux temperature for 2 hours. After cooling down to room temperature, the reaction mixture was stirred at room temperature for 12 hours under nitrogen. The reaction mixture was diluted with methylene chloride (250 mL), washed with saturated aqueous NaHCO3, water and brine. After drying (MgSO4), the solvent was removed under vacuum to give a yellow oil. Flash chromatography yielded the title compound (93, 3.34 g, 80%). TLC Rf 0.58 (70:30 hexane-ethyl acetate); MS (electrospray) 295, 297 (M+1); 1H N MR (CDCl3) δ1.57-1.84 (m, 3H), 2.16 (m, 2H), 2.55 (m, 1H), 3.75 (m, 1H), 4.01 (m, 1H), 4.65 (s, 2H), 5.71 (d, 1H, J=9.2 Hz), 7.44 (d, 1H, J=8.8 Hz), 7.59 (d, 1H, J=8.8 Hz), 7.73 (s, 1H), 8.00 (s, 1H).
Workup
- temperaturewas heated
- temperatureat reflux temperature for 2 hours
- washwashed with saturated aqueous NaHCO3, water and brine
- dry with materialAfter drying (MgSO4)
- customthe solvent was removed under vacuum
- customto give a yellow oil
Sources & evidence
- ORD record
- ord-579fe2a8e9764bc291f31210c5fa0e5b
- Source dataset
- uspto-grants-2003_04
- Patent number
- US06541467B1
Reaction notes
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