Benzyl Alcohol → 8-Fluoro-5-methoxychroman-3-y-carbamic acid benzyl ester
Reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]([O:15][CH3:16])=[C:6]2[C:11]=1[O:10][CH2:9][CH:8](C(O)=O)[CH2:7]2.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:24])C=CC=CC=1.C([N:36]([CH2:39]C)CC)C.[CH2:41]([OH:48])[C:42]1[CH:47]=[CH:46][CH:45]=[CH:44][CH:43]=1>C1(C)C=CC=CC=1>[CH2:41]([O:48][C:39](=[O:24])[NH:36][CH:8]1[CH2:7][C:6]2[C:11](=[C:2]([F:1])[CH:3]=[CH:4][C:5]=2[O:15][CH3:16])[O:10][CH2:9]1)[C:42]1[CH:47]=[CH:46][CH:45]=[CH:44][CH:43]=1Participants
Procedure
8-Fluoro-5-methoxychroman-3-yl carboxylic acid (1.12 g; 85.0 mmol), diphenyl phosphoryl azide (1.3 mL; 5.9 mmol) and toluene (10 mL) were mixed in a three-necked round-bottom flask (50 mL) under nitrogen. Triethylamine (0.83 mL; 5.9 mmol) was added and clear solution was stirred at 100° for 2 h. Benzylalcohol (0.61 mL; 5.9 mmol) was added in one portion and the stirring continued at 90° C. for 17 h. The volatiles were evaporated and the residue was taken up in toluene (25 mL). After Washing with 10% acetic acid (1×30 mL) and 2M ammonia (1×30 mL) the solution was dried (MgSO4), filtered and concentrated in vacuo to give a brown oil. Flash-chromatography of the crude product on a silica column eluted with ethyl acetate / toluene (3:97) afforded compound as an oil (contaminated with 2% unreacted isocyanate according to GC).
Workup
- waitthe stirring continued at 90° C. for 17 h
- customThe volatiles were evaporated
- washAfter Washing with 10% acetic acid (1×30 mL) and 2M ammonia (1×30 mL) the solution
- dry with materialwas dried (MgSO4)
- filtrationfiltered
- concentrationconcentrated in vacuo
- customto give a brown oil
- washFlash-chromatography of the crude product on a silica column eluted with ethyl acetate / toluene (3:97)
Sources & evidence
- ORD record
- ord-87707a6669ac4566b4034666591a33c5
- Source dataset
- uspto-grants-1997_08
- Patent number
- US05656658
Reaction notes
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