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

HRID 2260671Notes

Reaction equation

HRID 2260671 reaction equation
[NH2:1][C:2]1[C:7]([CH3:8])=[CH:6][C:5]([OH:9])=[C:4]([CH3:10])[C:3]=1[CH3:11].[CH3:12][C:13](=C)[CH2:14]O.S(=O)(=O)(O)O.[Cl:22][CH2:23]Cl>>[ClH:22].[NH2:1][C:2]1[C:7]([CH3:8])=[C:6]([CH3:23])[C:5]2[O:9][C:13]([CH3:14])([CH3:12])[CH2:10][C:4]=2[C:3]=1[CH3:11]

Participants

5

Reactant 4

HCID 1118Sulfuric AcidHCID 6344DichloromethaneHCID 10557Methallyl alcoholHCID 111055374-Amino-2,3,5-trimethylphenol

Product 1

HCID 102204225-Amino-2,2,4,6,7-pentamethyl-2,3-dihydrobenzofuran hydrochlorideYield 14.4%

Procedure

4-Amino-2,3,5-trimethylphenol (2.0 g, 13.2 mmol) and 2-methyl-2-propenol (1.15 g, 15.8 g) were heated under reflux in dichloromethane (20 ml) together with sulfuric acid (2 ml) for 18 hours. The reaction mixture was washed with aqueous saturated sodium bicarbonate solution, dried and then concentrated. The residue was purified by silica gel column chromatography (isopropyl ether). The purified product was converted into its hydrochloride and it was crystallized from ethanol-isopropyl ether to obtain the desired compound (460 mg, yield: 14.4%), m.p. 248°-250° C.

Workup

  1. washThe reaction mixture was washed with aqueous saturated sodium bicarbonate solution
  2. customdried
  3. concentrationconcentrated
  4. customThe residue was purified by silica gel column chromatography (isopropyl ether)
  5. customwas crystallized from ethanol-isopropyl ether

Sources & evidence

ORD record
ord-8e348221243e4365b426c5e81f3e5515
Source dataset
uspto-grants-1995_12
Patent number
US05478844

Reaction notes

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