Sulfuric Acid → 7-Hydroxy-2,2,4,5,8-pentamethyl chroman

HRID 1706712Notes

Reaction equation

HRID 1706712 reaction equation
[CH3:1][C:2]1[C:8]([OH:9])=[CH:7][C:6]([CH3:10])=[CH:5][C:3]=1[OH:4].S(=O)(=O)(O)O.[CH3:16][C:17]([CH3:22])=[CH:18][CH:19](O)[CH3:20]>C(OC(C)C)(C)C>[OH:4][C:3]1[C:2]([CH3:1])=[C:8]2[C:7]([CH:19]([CH3:20])[CH2:18][C:17]([CH3:22])([CH3:16])[O:9]2)=[C:6]([CH3:10])[CH:5]=1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 681032,5-DimethylresorcinolHCID 1381904-Methylpent-3-en-2-ol

Product 1

HCID 538418737-Hydroxy-2,2,4,5,8-pentamethyl chromanYield 60%

Reagents, catalysts & solvents 1

HCID 7914Diisopropyl EtherSolvent

Procedure

13.8 g. of 2,5-dimethyl resorcinol were dissolved in a mixed solution comprising 70 ml of isopropyl ether and 5 ml of concentrated sulfuric acid. Then, 10 g. of 4-methyl-3-pentene-2-ol were added dropwise to the solution at the temperature of about 60° C. for about 30 minutes. The resulting solution was cooled, and washed with water, with 1 N sodium hydroxide solution, and again with water and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure. The residue was recrystallized from ether/n-hexane, to obtain 13.2 g. (yield: 60%) of the subject compound. Melting point: 88°-89° C.

Workup

  1. temperatureThe resulting solution was cooled
  2. washwashed with water, with 1 N sodium hydroxide solution
  3. dry with materialagain with water and then dried over magnesium sulfate
  4. distillationThe solvent was distilled off under reduced pressure
  5. customThe residue was recrystallized from ether/n-hexane
  6. customto obtain 13.2 g

Sources & evidence

ORD record
ord-08935eef506b41c5954818af9df1a972
Source dataset
uspto-grants-1980_06
Patent number
US04208426

Reaction notes

Loading…