Formaldehyde → 2,2-Dimethyl-6-(1H-imidazol-1-YL)benzopyran

HRID 36616

Reaction equation

HRID 36616 reaction equation
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][C:9]([CH3:12])([CH3:11])[CH:8]=[CH:7][C:6]=2[CH:13]=1.[C:14]([O-])(=O)[CH3:15].[NH4+:18].[CH2:19]=O.C(C=O)=O.[OH-].[NH4+]>C(O)(=O)C.CO>[CH3:12][C:9]1([CH3:11])[CH:8]=[CH:7][C:6]2[CH:13]=[C:2]([N:1]3[CH:15]=[CH:14][N:18]=[CH:19]3)[CH:3]=[CH:4][C:5]=2[O:10]1

Participants

8

Reactant 5

HCID 712FormaldehydeHCID 7860GlyoxalHCID 14923Ammonium HydroxideHCID 517165Ammonium AcetateHCID 100808812,2-Dimethyl-2H-chromen-6-amine

Product 1

HCID 199376002,2-Dimethyl-6-(1H-imidazol-1-YL)benzopyran

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 887MethanolSolvent

Conditions

Temperature
65 °C

Procedure

To a stirred solution of 20 g (0.11 mol) of 6-amino-2,2-dimethylbenzopyran and 70 g (0.91 mol) of ammonium acetate in 190 mL of acetic acid and 770 mL of MeOH at 65° C. is added dropwise over 0.5 h, a mixture of 11.1 g (0.14 mol) of formaldehyde and 20g (0.14 mol) of glyoxal. The mixture is stirred for 1 hour at 65° C., then poured onto 800 g of ice. The pH of the solution is adjusted to 10 by the addition of concentrated ammonium hydroxide. The mixture is extracted with dichloromethane (3×200 mL) and the combined organic extracts are dried with sodium sulfate, filtered and evaporated under reduced pressure. The resulting oil is subjected to chromatography on silica gel utilizing 3% methanol in dichloromethane as eluent. The eluates are analyzed utilizing thin layer chromatography and appropriate fractions are combined and evaporated to produce the title compound.

Workup

  1. extractionThe mixture is extracted with dichloromethane (3×200 mL)
  2. dry with materialthe combined organic extracts are dried with sodium sulfate
  3. filtrationfiltered
  4. customevaporated under reduced pressure
  5. customevaporated

Sources & evidence

ORD record
ord-90b75e363fa247b8ab5b0c4afb592cd3
Source dataset
uspto-grants-1995_05
Patent number
US05416097

Linked notes

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