Ammonia → 2-Hydroxy-4-methoxybenzophenone

HRID 1111522Notes

Reaction equation

HRID 1111522 reaction equation
[OH:1][C:2]1[CH:15]=[C:14]([OH:16])[CH:13]=[CH:12][C:3]=1[C:4]([C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:5].[OH-].[Na+].S(OC)(O[CH3:23])(=O)=O.N>O>[OH:1][C:2]1[CH:15]=[C:14]([O:16][CH3:23])[CH:13]=[CH:12][C:3]=1[C:4]([C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:5]

Participants

6

Reactant 4

HCID 222AmmoniaHCID 6497Dimethyl Sulfate4×HCID 85722,4-DihydroxybenzophenoneHCID 14798Sodium Hydroxide2×

Product 1

HCID 46322-Hydroxy-4-methoxybenzophenoneYield 463.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

214 g ( =1.0 mole) of 2,4-dihydroxybenzophenone were added to a mixture of 500 ml of 2 N sodium hydroxide solution and 150 ml of water at room temperature and stirring was carried out until everything had dissolved (20 minutes). Thereafter, 31.6 ml (=0.33 mole) of dimethyl sulfate were added and stirring was continued for 0.5 hour, after which a further 31.6 ml (=0.33 mole) of dimethyl sulfate were added while stirring. After 0.5 hour, a further 31.6 ml (=0.33 mole) of dimethyl sulfate were added while stirring and, after 0.5 hour, 50 ml of 2 N sodium hydroxide solution and 9.5 ml of dimethyl sulfate were added. The mixture was stirred for 1 hour at room temperature, 30 ml of concentrated ammonia solution were added and stirring was then continued for a further 0.5 hour. The precipitate which had separated out was filtered off under suction and washed with a little water to give 349 g (202.4 g of dry product=89% of theory) of moist 2-hydroxy-4-methoxybenzophenone, which contains 1.07% of 2,4-dimethoxybenzophenone. The moist filtration residue was recrystallized from 1,170 ml of methanol with the addition of 5 g of active carbon. After filtration under suction and drying under reduced pressure from a water pump at 50° C., 171 g (=75% of theory) of pure 2-hydroxy-4-methoxybenzophenone of melting point 62°-63° C. were obtained. According to gas chromatography, the product did not contain any dimethoxy derivative.

Workup

  1. dissolutionhad dissolved (20 minutes)
  2. stirringstirring
  3. stirringwhile stirring
  4. waitAfter 0.5 hour
  5. stirringwhile stirring and, after 0.5 hour
  6. stirringThe mixture was stirred for 1 hour at room temperature
  7. stirringstirring
  8. waitwas then continued for a further 0.5 hour
  9. customThe precipitate which had separated out
  10. filtrationwas filtered off under suction
  11. washwashed with a little water

Sources & evidence

ORD record
ord-9dea3dd753ef485b9934d1d3394fc2f6
Source dataset
uspto-grants-1990_12
Patent number
US04980512

Reaction notes

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