Sulfuric Acid → 5-Amino-2,2,4,6,7-pentamethyl-2,3-dihydrobenzofuran

HRID 964802Notes

Reaction equation

HRID 964802 reaction equation
S(=O)(=O)(O)O.[NH2:6][C:7]1[C:12]([CH3:13])=[CH:11][C:10]([OH:14])=[C:9]([CH3:15])[C:8]=1[CH3:16].[CH3:17][C:18](=C)[CH2:19]O.[C:22](=O)(O)[O-].[Na+]>ClCCl>[NH2:6][C:7]1[C:12]([CH3:13])=[C:11]([CH3:22])[C:10]2[O:14][C:18]([CH3:19])([CH3:17])[CH2:15][C:9]=2[C:8]=1[CH3:16]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 10557Methallyl alcoholHCID 516892Sodium BicarbonateHCID 111055374-Amino-2,3,5-trimethylphenol

Product 1

HCID 100358625-Amino-2,2,4,6,7-pentamethyl-2,3-dihydrobenzofuranYield 16.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Sulfuric acid (2.0 ml) was added to a solution of 4-amino-2,3,5-trimethylphenol (2.0 g, 13.2 mmol) and 2-methyl-2-propenol (1.15 g, 15.8 mmol) in dichloromethane (20 ml) and the mixture was heated under reflux for 18 hours under an argon atmosphere. The reaction solution was made weak alkaline with aqueous saturated sodium bicarbonate solution and the organic layer was separated. The organic layer was washed with water, dried and then concentrated. The residue was purified by column chromatography on silica gel eluting with isopropyl ether. The product obtained was recrystallized from hexane to obtain the desired product as crystals (460 mg, yield: 16.9%), m.p. 110°-111° C.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 18 hours under an argon atmosphere
  3. customthe organic layer was separated
  4. washThe organic layer was washed with water
  5. customdried
  6. concentrationconcentrated
  7. customThe residue was purified by column chromatography on silica gel eluting with isopropyl ether
  8. customThe product obtained
  9. customwas recrystallized from hexane

Sources & evidence

ORD record
ord-48e6fde3d43c4fefa6a79b38a672c093
Source dataset
uspto-grants-1998_06
Patent number
US05770772

Reaction notes

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