Phthalide → 1(3H)-Isobenzofuranone, 3-bromo-

HRID 372610Notes

Reaction equation

HRID 372610 reaction equation
[C:1]1([C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][O:3]1)=[O:2].[Br:11]N1C(=O)CCC1=O.C1(=O)NC(=O)CC1>C(Cl)(Cl)(Cl)Cl>[Br:11][CH:4]1[C:5]2[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=2)[C:1](=[O:2])[O:3]1

Participants

5

Reactant 3

HCID 6885PhthalideHCID 11439SuccinimideHCID 67184N-bromobutanimide2×

Product 1

HCID 962181(3H)-Isobenzofuranone, 3-bromo-Yield 81%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

Phthalide (10.0 g; 0.075 moles) and N-bromosuccinimide were refluxed in dry carbon tetrachloride (200 ml.) in the presence of a catalytic amount of α-azo-iso-butyronitrile for 3-4 hours. The end of the reaction was indicated by the disappearance of N-bromosuccinimide from the bottom of the reaction vessel and the accumulation of succinimide at the top. The succinimide was removed by filtration and the filtrate concentrated in vacuo to 15-20 ml. Cooling of this concentrate followed by filtration gave 13.0 g. (81% yield) of crude 3-bromophthalide, m.p. 75-80°, as a white crystalline solid. The product was recrystallised from cyclohexane as colourless plates, m.p. 78-80° with a 95% recovery.

Workup

  1. customThe succinimide was removed by filtration
  2. concentrationthe filtrate concentrated in vacuo to 15-20 ml
  3. temperatureCooling of this concentrate
  4. filtrationfollowed by filtration
  5. customgave 13.0 g

Sources & evidence

ORD record
ord-f1f8388bb5e1423d93d9f96f5c42a667
Source dataset
uspto-grants-1978_05
Patent number
USRE029650

Reaction notes

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