Hydrochloric Acid → 2,2-Dimethyl-2H-chromen-6-amine

HRID 2245749Notes

Reaction equation

HRID 2245749 reaction equation
[CH3:1][C:2]1([CH3:15])[CH:7]=[CH:6][C:5]2[CH:8]=[C:9]([N+:12]([O-])=O)[CH:10]=[CH:11][C:4]=2[O:3]1.Cl.[OH-].[Na+]>O.C(O)C>[NH2:12][C:9]1[CH:10]=[CH:11][C:4]2[O:3][C:2]([CH3:1])([CH3:15])[CH:7]=[CH:6][C:5]=2[CH:8]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 103756666-Nitro-2,2-dimethylchromene

Product 1

HCID 100808812,2-Dimethyl-2H-chromen-6-amine

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 962WaterSolvent2×

Conditions

Temperature
60 °C

Procedure

2,2-dimethyl 6-nitro 2H-1-benzopyran (3), 40.1 g (185 mmol) was mixed with 120 g of ethanol, 28.0 g of water and 36.1 g of reduced iron, the resulting mixture was heated to 60° C., and a mixed solution of 4.0 g of 35% (w/w) hydrochloric acid, 16.0 g of ethanol and 4.0 g of water was added dropwise thereto over 50 minutes. After stirring at the same temperature for 2 hours, 10.0 g of 15% (w/w) sodium hydroxide aqueous solution was added dropwise thereto, the resulting mixture was filtered through celite, and then the solvent was distilled off. To 112 g of the resulting residue, 160 g of toluene and 68.0 g of 10% (w/w) sodium hydroxide aqueous solution were added, the resulting mixture was shaken, left and separated into phases. The aqueous phase was extracted with 68 g of toluene again. The organic phases were combined and washed with 68 g of 5% (w/w) sodium chloride solution, and the solvent was distilled off to obtain a solution of the intended product, 6-amino 2,2-dimethyl 6-2H-1-benzopyran (4) (68.0 g).

Workup

  1. filtrationthe resulting mixture was filtered through celite
  2. distillationthe solvent was distilled off
  3. additionTo 112 g of the resulting residue, 160 g of toluene and 68.0 g of 10% (w/w) sodium hydroxide aqueous solution were added
  4. stirringthe resulting mixture was shaken
  5. waitleft
  6. customseparated into phases
  7. extractionThe aqueous phase was extracted with 68 g of toluene again
  8. washwashed with 68 g of 5% (w/w) sodium chloride solution
  9. distillationthe solvent was distilled off

Sources & evidence

ORD record
ord-02626346dec445f1b3801774a3932035
Source dataset
uspto-grants-2010_03
Patent number
US07683189B2

Reaction notes

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