Acetone → 4-(1-(4-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl)phenyl)-1-methylethyl)phenyl cyanate

HRID 622148Notes

Reaction equation

HRID 622148 reaction equation
[O:1]=[C:2]1[CH:6]=[CH:5][C:4](=[O:7])[N:3]1[C:8]1[CH:13]=[CH:12][C:11]([C:14]([C:17]2[CH:22]=[CH:21][C:20]([OH:23])=[CH:19][CH:18]=2)([CH3:16])[CH3:15])=[CH:10][CH:9]=1.[N:24]#[C:25]Br.CC(C)=O.C(N(CC)CC)C>O>[O:1]=[C:2]1[CH:6]=[CH:5][C:4](=[O:7])[N:3]1[C:8]1[CH:9]=[CH:10][C:11]([C:14]([C:17]2[CH:18]=[CH:19][C:20]([O:23][C:25]#[N:24])=[CH:21][CH:22]=2)([CH3:16])[CH3:15])=[CH:12][CH:13]=1

Participants

6

Reactant 4

HCID 180AcetoneHCID 8471Triethylamine2×HCID 10476Cyanogen BromideHCID 19978531HCID 19978531, compound

Product 1

HCID 199676284-(1-(4-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl)phenyl)-1-methylethyl)phenyl cyanateYield 91.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
-5 °C

Procedure

A 21.70 gram portion of 4-(1-(4-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl)phenyl)-1-methylethyl)phenol (0.1037 mole), 11.53 grams of cyanogen bromide (0.1089 mole) and 250 milliliters of acetone were added to a reactor and maintained under a nitrogen atmosphere with stirring. The stirred solution was cooled to -5° C. then 10.55 grams of triethylamine (0.1043 mole) was added to the reactor over a eight minute (480 s) period and so as to maintain the reaction temperature at -5° to -3° C. After completion of the triethylamine addition, the reactor was maintained at -5° to -3° C. for an additional 37 minutes (2220 s), followed by addition of the reactor contents to 1500 milliliters of deionized water. After 5 minutes (300 s), the water and product mixture was multiply extracted with three 100 milliliter volumes of methylene chloride. The combined methylene chloride extract was washed with 500 milliliters of 0.05 percent aqueous hydrochloric acid followed by washing with 500 milliliters of deionized water then drying over anhydrous sodium sulfate. The dry methylene chloride extract was filtered and solvent removed by rotary evaporation under vacuum for 30 minutes (1800 s) at 90° C. 4-(1-(4-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl)phenyl)-1-methylethyl)phenyl cyanate (22.2 grams) was recovered in 91.4 percent yield as a light amber colored oil. Infrared spectrophotometric analysis of a film sample of the product confirmed the product structure (disappearance of phenolic hydroxyl absorbance, appearance of cyanate absorbance at 2242 and 2271 cm-1, maintenance of malemide carbonyl absorbance at 1722 cm-1).

Workup

  1. temperaturemaintained under a nitrogen atmosphere
  2. temperatureso as to maintain the reaction temperature at -5° to -3° C
  3. temperaturethe reactor was maintained at -5° to -3° C. for an additional 37 minutes (2220 s)
  4. extractionthe water and product mixture was multiply extracted with three 100 milliliter volumes of methylene chloride
  5. extractionThe combined methylene chloride extract
  6. washwas washed with 500 milliliters of 0.05 percent aqueous hydrochloric acid
  7. washby washing with 500 milliliters of deionized water
  8. dry with materialthen drying over anhydrous sodium sulfate
  9. extractionThe dry methylene chloride extract
  10. filtrationwas filtered
  11. customsolvent removed by rotary evaporation under vacuum for 30 minutes (1800 s) at 90° C
  12. custom4-(1-(4-(2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl)phenyl)-1-methylethyl)phenyl cyanate (22.2 grams) was recovered in 91.4 percent yield as a light amber colored oil

Sources & evidence

ORD record
ord-f775e57c8e144f789d618b326106c34d
Source dataset
uspto-grants-1988_09
Patent number
US04769440

Reaction notes

Loading…