Hydrochloric Acid → 4-Isocyanato-1,2-dimethoxybenzene

HRID 1773308Notes

Reaction equation

HRID 1773308 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:7]=[CH:8][C:9]=1[O:10][CH3:11])[NH2:6].Cl.[O:13]1CCOC[CH2:14]1.ClC(Cl)(OC(=O)OC(Cl)(Cl)Cl)Cl>>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([N:6]=[C:14]=[O:13])[CH:7]=[CH:8][C:9]=1[O:10][CH3:11]

Participants

5

Reactant 4

HCID 313Hydrochloric AcidHCID 227703,4-DimethoxyanilineHCID 312751,4-DioxaneHCID 94429Triphosgene

Product 1

HCID 35178104-Isocyanato-1,2-dimethoxybenzeneYield 97%

Conditions

Temperature
60 °C

Procedure

A 3 L, three-necked, round-bottomed flask was equipped with a heating/cooling bath, magnetic stirrer and stir bar, condenser, 500 mL addition funnel, thermocouple, nitrogen inlet, heating bath, vacuum distillation apparatus. To a stirred solution of 3,4-dimethoxyaniline (81.9 g, 535 mmol) in xylenes (1400 mL) was added via the addition funnel, a 4 N solution of hydrogen chloride in 1,4-dioxane (295 mL, 1180 mmol) at ambient temperature. This mixture was stirred at ˜25° C. for 30 minutes, before it was heated to reflux under a slow N2 stream. Neat triphosgene (200.0 g, 674 mmol) was added to the refluxing stirred mixture in portions via the addition funnel over 45 minutes. Upon completion of the addition, the batch was refluxed for another hour. After cooling to ˜60° C., the batch was concentrated under reduced pressure to remove most of the solvent. The oily residue was distilled under high vacuum (b.p. 84-88° C. @ 0.92 mmHg) to afford the title compound as an oil (93.0 g, 97%).

Workup

  1. customA 3 L, three-necked, round-bottomed flask was equipped with a heating/cooling bath, magnetic stirrer
  2. additionbar, condenser, 500 mL addition funnel
  3. temperaturethermocouple, nitrogen inlet, heating bath
  4. distillationvacuum distillation apparatus
  5. customat ambient temperature
  6. stirringThis mixture was stirred at ˜25° C. for 30 minutes, before it
  7. temperaturewas heated
  8. temperatureto reflux under a slow N2 stream
  9. stirringstirred mixture in portions via the addition funnel over 45 minutes
  10. additionUpon completion of the addition
  11. temperaturethe batch was refluxed for another hour
  12. concentrationthe batch was concentrated under reduced pressure
  13. customto remove most of the solvent
  14. distillationThe oily residue was distilled under high vacuum (b.p. 84-88° C. @ 0.92 mmHg)

Sources & evidence

ORD record
ord-730ed2029dab4d6483984da8ab6f4270
Source dataset
uspto-grants-2016_02
Patent number
US09255096B1

Reaction notes

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