Acetone → 2-(N-isopropylamino)-4-methylbenzophenone

HRID 652301Notes

Reaction equation

HRID 652301 reaction equation
[NH2:1][C:2]1[CH:15]=[C:14]([CH3:16])[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].[CH3:17][C:18]([CH3:20])=O.C1C=C(C(O)=O)C(C(O)=O)=CC=1.[BH4-].[Na+].[OH-].[Na+]>>[CH:18]([NH:1][C:2]1[CH:15]=[C:14]([CH3:16])[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])([CH3:20])[CH3:17]

Participants

6

Reactant 5

HCID 180AcetoneHCID 1017Phthalic AcidHCID 14798Sodium HydroxideHCID 786512-Amino-4-methylbenzophenoneHCID 4311764Sodium borohydride

Product 1

HCID 128985342-(N-isopropylamino)-4-methylbenzophenoneYield 99%

Conditions

Temperature
50 °C

Procedure

422.6 g. (2 moles) of 2 amino-4-methylbenzophenone is dissolved in 2.34 liters (40.29 moles) of acetone, and with stirring 540 gms (3.25 moles) of o-phthalic acid is added. To the resulting suspension is added portionwise 80 gms (2.14 moles) of sodium borohydride over a period of 45 minutes and in a manner such as to keep the reaction mixture at 20°-25° C. At the end of the addition, the cooling is altered such as to allow the temperature to rise to 30°-35° C., and this temperature is maintained for 30 minutes. The cooling is removed and the temperature carefully increased to 50° C., and regulated at 50°-55° C. for 90 minutes. The mixture is then cooled to 15° C., 808 gms of 8% aqueous NaOH (1.625 moles) is added, the phases separated and the acetone phase (upper layer) recovered and concentrated. The water layer is extracted with 1 litre of heptane, and the concentrated acetone phase added to the heptane extract. The heptane solution is washed with 250 mls of H2O, then concentrated by distillation to obtain 496 gms of 2-(N-isopropylamino)-4-methylbenzophenone, b.p. 180°-185° C./5mm (Yield 99%).

Workup

  1. additionis added
  2. customat 20°-25° C
  3. additionAt the end of the addition
  4. customto rise to 30°-35° C.
  5. temperaturethis temperature is maintained for 30 minutes
  6. customThe cooling is removed
  7. temperatureThe mixture is then cooled to 15° C.
  8. customthe phases separated
  9. customthe acetone phase (upper layer) recovered
  10. concentrationconcentrated
  11. extractionThe water layer is extracted with 1 litre of heptane
  12. additionthe concentrated acetone phase added to the heptane
  13. extractionextract
  14. washThe heptane solution is washed with 250 mls of H2O
  15. concentrationconcentrated by distillation

Sources & evidence

ORD record
ord-2a65f4565dee4289867b6bef36b2db57
Source dataset
uspto-grants-1987_06
Patent number
US04670600

Reaction notes

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