Imidazole → 1,1'-Carbonyldiimidazole

HRID 1835909Notes

Reaction equation

HRID 1835909 reaction equation
Cl[C:2]1[CH:7]=CC=CC=1.[NH:8]1[CH:12]=[CH:11][N:10]=[CH:9]1.[OH-:13].[Na+]>O>[C:12]([N:8]1[CH:2]=[CH:7][N:10]=[CH:9]1)([N:8]1[CH:12]=[CH:11][N:10]=[CH:9]1)=[O:13]

Participants

5

Reactant 3

HCID 795ImidazoleHCID 7964ChlorobenzeneHCID 14798Sodium Hydroxide

Product 1

HCID 682631,1'-CarbonyldiimidazoleYield 79.5%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
90 °C

Procedure

1200 g of chlorobenzene and 272.4 g of imidazole were introduced into a flask fitted with water separator. 320 g of 50% strength by weight sodium hydroxide solution were added dropwise. Water was separated out until the distillate no longer separated into two phases. After 224 ml of water had been separated out in this way, 100 ml of chlorobenzene were removed by distillation, then 2 g of tributylhexadecylphosphonium bromide were added, and 202 g of phosgene were passed in at 80-85° C. over the course of one hour. When the addition was complete, the mixture was stirred at 90° C. for a further 1 hour while a vigorous stream of nitrogen was passed through the flask. The precipitate then present was filtered off at 80° C. and rinsed with 200 g of chlorobenzene at 90° C. The filtrate and the washing liquid were combined and cooled to 0° C. The precipitate which deposited was filtered off, rinsed with 200 g of dry chlorobenzene and dried at 60° C. under reduced pressure (50 mbar). 266 g of carbonyldiimidazole in the form of colorless crystals were obtained in a purity of 97.0%. This corresponded to a yield of 79.5% of theory.

Workup

  1. customWater was separated out until the distillate
  2. customno longer separated into two phases
  3. customAfter 224 ml of water had been separated out in this way, 100 ml of chlorobenzene
  4. customwere removed by distillation
  5. addition2 g of tributylhexadecylphosphonium bromide were added
  6. customwere passed in at 80-85° C. over the course of one hour
  7. additionWhen the addition
  8. filtrationThe precipitate then present was filtered off at 80° C.
  9. washrinsed with 200 g of chlorobenzene at 90° C
  10. temperaturecooled to 0° C
  11. filtrationThe precipitate which deposited was filtered off
  12. washrinsed with 200 g of dry chlorobenzene
  13. customdried at 60° C. under reduced pressure (50 mbar)

Sources & evidence

ORD record
ord-0beee09b86ca495dbd97e1da5ae155a6
Source dataset
uspto-grants-2004_08
Patent number
US06774239B2

Reaction notes

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