Pinacolone → methyl 5,5-dimethyl-2,4-dioxohexanoate

HRID 649343Notes

Reaction equation

HRID 649343 reaction equation
C[O-].[Na+].ClC1C=CC=CC=1.CO[C:13](=[O:18])[C:14]([O:16][CH3:17])=[O:15].[CH3:19][C:20]([C:22]([CH3:25])([CH3:24])[CH3:23])=[O:21]>CO>[CH3:17][O:16][C:14](=[O:15])[C:13]([CH2:19][C:20](=[O:21])[C:22]([CH3:25])([CH3:24])[CH3:23])=[O:18]

Participants

6

Reactant 4

HCID 6416PinacoloneHCID 7964ChlorobenzeneHCID 11120Dimethyl oxalateHCID 10942334Sodium Methoxide

Product 1

HCID 4016750methyl 5,5-dimethyl-2,4-dioxohexanoate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
10 °C

Procedure

198 g of methanolic sodium methyate solution (30% strength by weight) are added to 400 g of chlorobenzene. The methanol is distilled off at 65° C. in the course of 1 hour. The mixture is cooled to 10° C. and 118 g (1 mol) of molten oxalic acid dimethyl ester are introduced in the course of 1 hour. Thereafter, 100 g (1 mol) of pinacolin are allowed to run in and the mixture is subsequently stirred at room temperature for 15 minutes. It is heated, and the methanol formed in the reaction is distilled off in the course of 2 hours. Neutralisation with sulphuric acid, separation of the phases and distillation of the organic phase gives 165 g of pivaloylpyruvic acid methyl ester (87.8% of the theoretical yield). Purity: 99.0%.

Workup

  1. distillationThe methanol is distilled off at 65° C. in the course of 1 hour
  2. temperatureIt is heated
  3. distillationis distilled off in the course of 2 hours
  4. customNeutralisation with sulphuric acid, separation of the phases and distillation of the organic phase

Sources & evidence

ORD record
ord-c677b96512394f8aad7c3b4cc269a35a
Source dataset
uspto-grants-1988_04
Patent number
US04739104

Reaction notes

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