Benzophenone, 2,2',5-trimethoxy- → 2-Hydroxyxanthone

HRID 1197190Notes

Reaction equation

HRID 1197190 reaction equation
CO[C:3]1[CH:18]=[CH:17][C:16]([O:19]C)=[CH:15][C:4]=1[C:5]([C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1[O:13]C)=[O:6].Cl.N1C=CC=CC=1>>[OH:19][C:16]1[CH:17]=[CH:18][C:3]2[O:13][C:8]3[C:7](=[CH:12][CH:11]=[CH:10][CH:9]=3)[C:5](=[O:6])[C:4]=2[CH:15]=1

Participants

3

Reactant 2

HCID 36279Benzophenone, 2,2',5-trimethoxy-HCID 10176127Pyridinium chloride

Product 1

HCID 747082-Hydroxyxanthone

Procedure

A mixture of 2,2',5-trimethoxybenzophenone (6.52 g, 23,9 mmol, unpurified) prepared as described above, and pyridine hydrochloride (35.0 g, 0.3 mol) was refluxed (~210° C.) for 48 hours under N2. The mixture was then poured into ice (100 g), and the yellow-green precipitate which formed was collected by filtration and washed with water (2×60 mL). This residue was then suspended in water (~60 mL), and made alkaline (pH~12) with 45% (w/v) aqueous KOH. The resultant reddish-brown suspension was filtered, and added dropwise to a stirred mixture of ice (50 g) and 12N HCl (15 mL). The precipitated solid was filtered, washed with water (4×20 mL), and air dried. Yield: 4.25 g (84%). TLC: Rf 0.54 [benzene-EtOH (20:3)]. 1H-NMR (DMSO, 200 MHz) δ:8.17 (dd,J=1.5 and 7.9 Hz, 1H), 7.85 (t,J=7.7 Hz, 1H), 7.41-7.66 (m, 4H), 7.32 (dd,J=9.0 and 3.1 Hz, 1H). ##STR4##

Workup

  1. customprepared
  2. temperaturewas refluxed (~210° C.) for 48 hours under N2
  3. customthe yellow-green precipitate which formed
  4. filtrationwas collected by filtration
  5. washwashed with water (2×60 mL)
  6. filtrationThe resultant reddish-brown suspension was filtered
  7. additionadded dropwise to a stirred mixture of ice (50 g) and 12N HCl (15 mL)
  8. filtrationThe precipitated solid was filtered
  9. washwashed with water (4×20 mL), and air
  10. customdried

Sources & evidence

ORD record
ord-75c14a080b19477ba35ecf4b26a6acb5
Source dataset
uspto-grants-1992_05
Patent number
US05117009

Reaction notes

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