Methanol → 2-Methoxyxanthone

HRID 1275523Notes

Reaction equation

HRID 1275523 reaction equation
[C:1]([C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH3:15][O-:16].[Na+].C[OH:19].O>CCO>[CH3:15][O:16][C:4]1[CH:5]=[CH:6][C:7]2[O:19][C:14]3[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=3)[C:1](=[O:8])[C:2]=2[CH:3]=1

Participants

6

Reactant 4

HCID 887MethanolHCID 962WaterHCID 3102BenzophenoneHCID 10942334Sodium Methoxide

Product 1

HCID 710342-MethoxyxanthoneYield 91.6%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

The benzophenone intermediate was then stirred in EtOH (400 ml) at room temperature and treated with a solution of NaOMe in MeOH (25 wt. %, 45.72 ml, 0.2 mole). The color of the reaction mixture changed to burgundy right away. The reaction mixture was brought to reflux for 1 hr and 20 min, TLC showed that the reaction was complete. After brief cooling, water (500 ml) was added while the mixture was still warm and a yellow powder precipitated. The suspension was stored in refrigerator overnight. The solid was filtered on a Buchner funnel and washed with cold water. 2-Methoxy-9H-xanthen-9-one 1 (20.7 g, 91.6%) was obtained as a light yellow powder: m.p. 128-130° C.; 1H NMR (CDCl3): delta 8.33 (1H, dd, J=7.9, 1.8 Hz), 7.67-7.72 (2H, m), 7.47 (1H, d, J=8.6 Hz), 7.42 (1H, d, J=9.2 Hz), 7.35 (1H, m), 7.31 (1H, dd, J=9.2, 3.1 Hz) and 3.90 (3H, s); 1R (CHCl3): 2998, 1635, 1610, 1480, 1463, 1430, 1313, 1266, 1140, 1108, 1038, 852 and 823 cm-1.

Workup

  1. temperatureto reflux for 1 hr and 20 min
  2. temperaturewas still warm
  3. customa yellow powder precipitated
  4. customwas stored in refrigerator overnight
  5. filtrationThe solid was filtered on a Buchner funnel
  6. washwashed with cold water

Sources & evidence

ORD record
ord-898f34376bc14326b3f95ff00a3490d9
Source dataset
uspto-grants-2000_12
Patent number
US06162610

Reaction notes

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