Ammonia → 2-(1-Propenyl)-7,7-dimethyl-6,7-dihydro-3H,5H-pyrrolo[2,3-f]benzimidazol-6-one

HRID 568812Notes

Reaction equation

HRID 568812 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][C:10]=1[NH2:11])[NH:7][C:6](=[O:12])[C:5]2([CH3:14])[CH3:13].[C:15](O)(=O)/[CH:16]=[CH:17]/[CH3:18].N>O>[CH:16]([C:15]1[NH:11][C:10]2[CH:9]=[C:8]3[NH:7][C:6](=[O:12])[C:5]([CH3:14])([CH3:13])[C:4]3=[CH:3][C:2]=2[N:1]=1)=[CH:17][CH3:18]

Participants

5

Reactant 3

HCID 222AmmoniaHCID 637090Crotonic AcidHCID 135892372H-Indol-2-one, 5,6-diamino-1,3-dihydro-3,3-dimethyl-

Product 1

HCID 1784398432-(1-Propenyl)-7,7-dimethyl-6,7-dihydro-3H,5H-pyrrolo[2,3-f]benzimidazol-6-one

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

Analogously to Example 11, 0.95 g. 5,6-diamino-3,3-dimethylindolin-2-one and 0.43 g. crotonic acid are heated with 10 ml. polyphosphoric acid for 30 minutes at 170° C. (bath temperature). The cooled reaction mixture is dissolved in 40 ml. water and neutralised with concentrated aqueous ammonia solution. Insoluble material is filtered off with suction, washed with water and dissolved in 100 ml. hot ethanol. After treatment with active charcoal, the hot filtrate is evaporated in a vacuum and the evaporation residue is triturated with diethyl ether. There is thus obtained 0.7 g. of the title compound which contains 0.5 mole of water per mole of substance; m.p. 252°-254° C.

Workup

  1. customThe cooled reaction mixture
  2. dissolutionis dissolved in 40 ml
  3. filtrationInsoluble material is filtered off with suction
  4. washwashed with water
  5. dissolutiondissolved in 100 ml
  6. customAfter treatment with active charcoal, the hot filtrate is evaporated in a vacuum
  7. customthe evaporation residue is triturated with diethyl ether

Sources & evidence

ORD record
ord-c3cd393b2c7845a891c232aede4588d3
Source dataset
uspto-grants-1988_03
Patent number
US04730003

Reaction notes

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