Water → 2,2-Dimethyl-2H-chromen-6-amine

HRID 2245748Notes

Reaction equation

HRID 2245748 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.O.NN.O>C(O)C.[Pt]>[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 962WaterHCID 24654Hydrazine hydrate (1:1)HCID 103756666-Nitro-2,2-dimethylchromene

Product 1

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

Reagents, catalysts & solvents 2

HCID 23939PlatinumCatalystHCID 702EthanolSolvent

Conditions

Temperature
35 °C

Procedure

Ten grams (10 g, 48.7 mmol) of 2,2-dimethyl 6-nitro 2H-1-benzopyran (3) was dissolved in 60.0 g of ethanol under heating. After cooling to 35° C., 0.6 g of 2% Pt—C (50% water-containing product) was added thereto, and 5.85 g (117.0 mmol) of hydrazine monohydrate (98% product) was added dropwise (dropwise adding was continued for 30 minutes) while controlling internal temperature to 40° C. or less. After completion of dropwise adding, reaction was carried out at a temperature of 40 to 45° C. for 6 hours. The resulting solution was cooled to room temperature, and then 10.0 g of water was added thereto and the resulting solution was filtered through celite. The celite was washed with 20.0 g of 80% water-containing ethanol, and the washing together with the filtrate were subjected to solvent-distillation. The residue was extracted with 40.0 g of toluene and 20.0 g of water. After separating into phases, the aqueous phase was extracted with 20.0 g toluene again. The toluene phases were combined, washed with 20.0 g of water and then subjected to solvent-distillation to obtain a crude product of intended product (4).

Workup

  1. temperatureunder heating
  2. additiondropwise adding
  3. customto 40° C. or less
  4. additionAfter completion of dropwise adding
  5. customreaction
  6. waitwas carried out at a temperature of 40 to 45° C. for 6 hours
  7. temperatureThe resulting solution was cooled to room temperature
  8. filtrationthe resulting solution was filtered through celite
  9. washThe celite was washed with 20.0 g of 80% water-
  10. additioncontaining ethanol
  11. distillationthe washing together with the filtrate were subjected to solvent-distillation
  12. extractionThe residue was extracted with 40.0 g of toluene and 20.0 g of water
  13. customAfter separating into phases
  14. extractionthe aqueous phase was extracted with 20.0 g toluene again
  15. washwashed with 20.0 g of water
  16. distillationsubjected to solvent-distillation

Sources & evidence

ORD record
ord-4a8813e9bab642a4b7f656c2125f353b
Source dataset
uspto-grants-2010_03
Patent number
US07683189B2

Reaction notes

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