Ammonium formate → Ethyl 5-amino-1-methyl-1H-indole-2-carboxylate

HRID 2085875Notes

Reaction equation

HRID 2085875 reaction equation
[CH3:1][N:2]1[C:10]2[C:5](=[CH:6][C:7]([N+:11]([O-])=O)=[CH:8][CH:9]=2)[CH:4]=[C:3]1[C:14]([O:16][CH2:17][CH3:18])=[O:15].C([O-])=O.[NH4+]>[Pd].C(O)C.O>[NH2:11][C:7]1[CH:6]=[C:5]2[C:10](=[CH:9][CH:8]=1)[N:2]([CH3:1])[C:3]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[CH:4]2

Participants

6

Reactant 2

HCID 2723923Ammonium formateHCID 10538482ethyl 1-methyl-5-nitro-1H-indole-2-carboxylate

Product 1

HCID 11424506Ethyl 5-amino-1-methyl-1H-indole-2-carboxylateYield 86%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 702EthanolSolventHCID 962WaterSolvent

Conditions

Temperature
20 °C

Procedure

Alternative A. To a mixture of ethyl 1-methyl-5-nitro-1H-indole-2-carboxylate (420 g), from step (a) or commercial sources, and 10% palladium on carbon catalyst (50% wet) (42 g) in ethanol (4200 mL) was added a solution of ammonium formate (541.5 g) in demineralized water (840 mL) at between 25-35° C. over 3 hours. The mixture was stirred for 18 hours at 20° C., and then filtered, washing the solids with ethanol (2100 mL). The combined filtrate and washings were concentrated to 840 mL under vacuum at about 20° C. The resulting slurry was granulated at 5° C., filtered, washed with chilled ethanol (420 mL), and dried to give product ethyl 5-amino-1-methyl-1H-indole-2-carboxylate (316.5 g, 86%).

Workup

  1. filtrationfiltered
  2. washwashing the solids with ethanol (2100 mL)
  3. concentrationThe combined filtrate and washings were concentrated to 840 mL under vacuum at about 20° C
  4. customwas granulated at 5° C.
  5. filtrationfiltered
  6. washwashed with chilled ethanol (420 mL)
  7. customdried

Sources & evidence

ORD record
ord-0715ead830474b50bdcc8df2c5bd206d
Source dataset
uspto-grants-2004_04
Patent number
US06720351B2

Reaction notes

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