Phosgene → Piperonal

HRID 236698Notes

Reaction equation

HRID 236698 reaction equation
[CH2:1]1[O:9][C:4]2[CH:5]=[CH:6][CH:7]=[CH:8][C:3]=2[O:2]1.CN([CH:18]=[O:19])C1C=CC=CC=1.C(Cl)(Cl)=O>>[CH:6]1[C:7]([CH:18]=[O:19])=[CH:8][C:3]2[O:2][CH2:1][O:9][C:4]=2[CH:5]=1

Participants

4

Reactant 3

HCID 6371PhosgeneHCID 92291,3-Benzodioxole3×HCID 66737N-Methylformanilide

Product 1

HCID 8438PiperonalYield 64%

Conditions

Temperature
15 °C

Procedure

Into a mixture of 97.6 g (0.80 mole) of 1,2-methylenedioxybenzene and 108 g (0.80 mole) of N-methylformanilide was introduced 87.1 g (0.88 mole) of phosgene at 50° C. over a 1-hour period. Then, the mixture was cooled to 15° C. On the other hand, 29.3 g (0.24 mole) of 1,2-methylenedioxybenzene was charged into another reactor and kept at 90° C. The above mixture was added to this reactor over a 5-hour period. After completion of the addition, the reaction mixture was kept at 90° C. for 30 minutes, poured into ice water, and allowed to stand for 1 hour. Then, the resulting mixture was extracted with toluene. By vacuum distillation, the toluene was removed and the distillate at 84°-85° C./30 mmHg was then collected to recover 63.4 g (0.52 mole) of unreacted 1,2-methylenedioxybenzene. Subsequently, the distillate at 131°-134° C./10 mmHg was collected to obtain 76.8 g (0.512 mole) of piperonal having a purity of 99.5%. The yield (expressed in terms of mole percentage based on the amount of N-methylformanilide used) and selectivity (expressed in terms of mole percentage based on the amount of 1,2-methylenedioxybenzene having reacted) of piperonal were 64.0% and 98.5%, respectively. This product had a melting point of 37° C.

Workup

  1. customkept at 90° C
  2. additionThe above mixture was added to this reactor over a 5-hour period
  3. additionAfter completion of the addition
  4. waitto stand for 1 hour
  5. extractionThen, the resulting mixture was extracted with toluene
  6. distillationBy vacuum distillation
  7. customthe toluene was removed
  8. distillationthe distillate at 84°-85° C./30 mmHg was then collected
  9. distillationSubsequently, the distillate at 131°-134° C./10 mmHg was collected

Sources & evidence

ORD record
ord-0151e9b7b9324945b33ffcbd2b44ea11
Source dataset
uspto-grants-1979_06
Patent number
US04157333

Reaction notes

Loading…