Hydrochloric Acid → 2-(4-Tert-butyl-2,6-dimethylphenyl)acetic acid

HRID 1183852Notes

Reaction equation

HRID 1183852 reaction equation
[C:1]([C:5]1[CH:15]=[C:14]([CH3:16])[C:8]([CH:9](O)[C:10]([OH:12])=[O:11])=[C:7]([CH3:17])[CH:6]=1)([CH3:4])([CH3:3])[CH3:2].C(O)(=O)C.C(C1C=C(C)C(C(O)C(O)=O)=C(C)C=1)(C)(C)C.Cl>C(O)(=O)C>[C:1]([C:5]1[CH:6]=[C:7]([CH3:17])[C:8]([CH2:9][C:10]([OH:12])=[O:11])=[C:14]([CH3:16])[CH:15]=1)([CH3:4])([CH3:3])[CH3:2]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 52915831Xylometazoline Impurity 20HCID 674987574-tert-Butyl-2,6-dimethylmandelic acid acetate

Product 1

HCID 529158172-(4-Tert-butyl-2,6-dimethylphenyl)acetic acidYield 86%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of 2.89 g of 4-tert-butyl-2,6-dimethylmandelic acid and 7.75 g of 4-tert-butyl-2,6-dimethylmandelic acid acetate, 4.5 g of 37% strength hydrochloric acid, 1.86 g of red phosphorus and 0.66 g of KI in 30 ml of glacial acetic acid is heated at 100° C. for 16 hours. Excess phosphorus is filtered off with suction and washed three times with in each case 10 ml of glacial acetic acid. The filtrate is substantially concentrated on a rotary evaporator at a bath temperature of 50° C./60 mbar. The resulting residue is diluted with 25 ml of water and, by addition of 10% strength aqueous sodium hydroxide solution, dissolved. This solution is extracted twice with in each case 20 ml of MTBE and then adjusted to pH 1 using 48% strength sulfuric acid. The resulting greasy solid is taken up in methylene chloride. This solution is extracted with 25 ml of water, dried over sodium sulfate and concentrated using a rotary evaporator. This gives 7.66 g of 4-tert-butyl-2,6-dimethylphenylacetic acid in a purity of 99.0 GC area % (yield about 86% of theory).

Workup

  1. filtrationExcess phosphorus is filtered off with suction
  2. washwashed three times with in each case 10 ml of glacial acetic acid
  3. concentrationThe filtrate is substantially concentrated on a rotary evaporator at a bath temperature of 50° C./60 mbar
  4. additionThe resulting residue is diluted with 25 ml of water and, by addition of 10% strength aqueous sodium hydroxide solution
  5. dissolutiondissolved
  6. extractionThis solution is extracted twice with in each case 20 ml of MTBE
  7. extractionThis solution is extracted with 25 ml of water
  8. dry with materialdried over sodium sulfate
  9. concentrationconcentrated
  10. customa rotary evaporator

Sources & evidence

ORD record
ord-b828432b47e24fc0a694b0f4dbe5d9a0
Source dataset
uspto-grants-2014_03
Patent number
US08664428B2

Reaction notes

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