Pyridine → trifluoromethanesulfonic acid 1-hydroxy-9-oxo-9H-xanthen-3-yl ester
Reaction equation
[F:1][C:2]([F:15])([F:14])[S:3]([O:6]S(C(F)(F)F)(=O)=O)(=[O:5])=[O:4].[OH:16][C:17]1[C:30]2[C:29](=[O:31])[C:28]3[C:23](=[CH:24][CH:25]=[CH:26][CH:27]=3)[O:22][C:21]=2[CH:20]=[C:19](O)[CH:18]=1.N1C=CC=CC=1>C(Cl)Cl>[OH:16][C:17]1[C:30]2[C:29](=[O:31])[C:28]3[C:23](=[CH:24][CH:25]=[CH:26][CH:27]=3)[O:22][C:21]=2[CH:20]=[C:19]([O:6][S:3]([C:2]([F:15])([F:14])[F:1])(=[O:5])=[O:4])[CH:18]=1Participants
Procedure
Trifluoromethanesulfonic anhydride (0.54 mL, 3.21 mmol) was added slowly to a solution of, 1,3-dihydroxyxanthen-9-one (689 mg, 3.02 mmol) and pyridine (7.3 mL) in CH2Cl2 (30 mL) at 0° C. The reaction then was allowed to slowly warm to RT and stirred for 16 h. The orange mixture then was dissolved in CH2Cl2 (100 mL), and washed with 10% citric acid (2×25 mL) and brine (1×25 mL). The organics were dried (Na2SO4), concentrated, and purified by Biotage chromatography using 10% EtOAc/hexanes as eluent to yield 702 mg (65%) of trifluoromethanesulfonic acid 1-hydroxy-9-oxo-9H-xanthen-3-yl ester as a light yellow solid. Rf=0.65 (50% EtOAc/hexanes). See R. Pillai et al., J. Org. Chem., 51, pages 717-723 (1986). 1H NMR (DMSO-d6, 400 MHz) δ: 12.90 (s, 1H), 8.20 (d, 1H), 7.96 (dd, 1H), 7.70 (d, 1H), 7.56 (dd, 1H), 7.37 (m, 1H), 7.05 (m, 1H).
Workup
- customThe reaction
- washwashed with 10% citric acid (2×25 mL) and brine (1×25 mL)
- dry with materialThe organics were dried (Na2SO4)
- concentrationconcentrated
- custompurified by Biotage chromatography
Sources & evidence
- ORD record
- ord-01f5dd3620114834bdea01772ce4c307
- Source dataset
- uspto-grants-2013_03
- Patent number
- US08404681B2
Reaction notes
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