Ammonia → 3-Methoxy-4-methyl-4H-furo[3,2-b]indole-2-carboxamide

HRID 1982413Notes

Reaction equation

HRID 1982413 reaction equation
C(=O)=O.CC(C)=O.[NH3:8].C([O:11][C:12]([C:14]1[O:25][C:24]2[C:23]3[CH:22]=[CH:21][CH:20]=[CH:19][C:18]=3[N:17]([CH3:26])[C:16]=2[C:15]=1[O:27][CH3:28])=O)C>O1CCCC1>[CH3:28][O:27][C:15]1[C:16]2[N:17]([CH3:26])[C:18]3[CH:19]=[CH:20][CH:21]=[CH:22][C:23]=3[C:24]=2[O:25][C:14]=1[C:12]([NH2:8])=[O:11]

Participants

5

Reactant 3

HCID 222AmmoniaHCID 13220386HCID 13220386, compoundHCID 18522661Acetone cardice

Product 1

HCID 132203963-Methoxy-4-methyl-4H-furo[3,2-b]indole-2-carboxamideYield 79%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A flask fitted with a Dewar condenser containing dry ice/acetone was cooled in a dry ice/acetone bath and charged with 350 ml of anhydrous ammonia. A few crystals of hydrated ferric nitrate catalyst were added, and the cooling bath was removed. Lithium amide was then generated by the addition, over one hour, of 1.78 g (0.26 mole) of freshly cut lithium metal ribbon. After the addition of 65 ml of cold tetrahydrofuran, a solution of 16.5 g (0.060 mole) of 3-methoxy-4-methyl-4H-furo[3,2-b]indole-2-carboxylic acid ethyl ester in 75 ml of tetrahydrofuran was added over 30 minutes. The Dewar condenser was removed, and the mixture was stirred for 16 hours as the excess ammonia evaporated. The total reaction mixture was added to 600 g of ice/water, and the crude amide product was filtered and washed with water. Recrystallization from aqueous ethanol yielded 11.7 g (79% yield) of final product, mp 174°-177° C. An additional recrystallization as above yielded an analytically pure sample, mp 179°-182° C.

Workup

  1. customA flask fitted with a Dewar condenser
  2. temperaturewas cooled in a dry ice/acetone bath
  3. customthe cooling bath was removed
  4. additionLithium amide was then generated by the addition, over one hour, of 1.78 g (0.26 mole) of freshly cut lithium metal ribbon
  5. additionAfter the addition of 65 ml of cold tetrahydrofuran
  6. customThe Dewar condenser was removed
  7. customevaporated
  8. customThe total reaction mixture
  9. filtrationthe crude amide product was filtered
  10. washwashed with water
  11. customRecrystallization from aqueous ethanol

Sources & evidence

ORD record
ord-96e9d4ee62704b68a9eb70d33c2c9981
Source dataset
uspto-grants-1986_06
Patent number
US04596814

Reaction notes

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