Trifluoroacetic acid → 3-acetyl-10,11-dihydro-5H-dibenzo(c,g)chromen-8(9H)-one
Reaction equation
C[Si]([C:5]#[C:6][C:7]1[CH:8]=[CH:9][C:10]2[C:19]3[CH:18]=[C:17]4[CH2:20][CH2:21][CH2:22][C:23](=[O:24])[C:16]4=[CH:15][C:14]=3[O:13][CH2:12][C:11]=2[CH:25]=1)(C)C.C(O)(C(F)(F)F)=[O:27]>>[C:6]([C:7]1[CH:8]=[CH:9][C:10]2[C:19]3[CH:18]=[C:17]4[CH2:20][CH2:21][CH2:22][C:23](=[O:24])[C:16]4=[CH:15][C:14]=3[O:13][CH2:12][C:11]=2[CH:25]=1)(=[O:27])[CH3:5]Participants
Conditions
- Temperature
- 65 °C
Procedure
A 20 mL vial with stir bar was charged with 3-((trimethylsilyl)ethynyl)-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one (850 mg, 2.44 mmol) and TFA (9.8 mL). The solution was heated to 65° C. After 3 h, the reaction was judged complete. The mixture was concentrated under reduced pressure; the resulting residue was taken up in CH2Cl2 and loaded onto a prepacked 25 g silica gel cartridge. The product was purified by chromatography on a prepacked 80 g silica gel column eluting with a solvent gradient from 5% to 85% EtOAc/hexanes. The product containing fractions were combined and concentrated to provide 3-acetyl-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one (616 mg, 86%): 400 MHz 1H NMR (CDCl3) δ 8.00-7.94 (m, 1H), 7.81 (d, J=8.2 Hz, 1H), 7.77 (s, 1H), 7.64 (s, 2H), 5.16 (s, 2H), 2.98 (t, J=6.1 Hz, 2H), 2.69-2.64 (m, 2H), 2.63 (s, 3H), 2.21-2.09 (m, 2H).
Workup
- concentrationThe mixture was concentrated under reduced pressure
- customThe product was purified by chromatography on a prepacked 80 g silica gel column
- washeluting with a solvent gradient from 5% to 85% EtOAc/hexanes
- additionThe product containing fractions
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-acb89fa8dae2464797be7decd1ebc0bb
- Source dataset
- uspto-grants-2015_06
- Patent number
- US09051340B2
Reaction notes
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