Ethyl 3-phenylprop-2-enoate → Ethyl 2-amino-1-benzothiophene-3-carboxylate

HRID 2086329Notes

Reaction equation

HRID 2086329 reaction equation
C([NH:4][C:5]1(C(OCC)=O)[CH2:9][CH:8]2[CH2:10][CH2:11][CH2:12][CH:13]=[C:7]2[S:6]1)(=O)C.[C:19]([O:29][CH2:30][CH3:31])(=[O:28])C=CC1C=CC=CC=1.N1CCCC1>[Pd].C1(C)C=C(C)C=C(C)C=1>[NH2:4][C:5]1[S:6][C:7]2[CH:13]=[CH:12][CH:11]=[CH:10][C:8]=2[C:9]=1[C:19]([O:29][CH2:30][CH3:31])=[O:28]

Participants

6

Reactant 3

HCID 7649Ethyl 3-phenylprop-2-enoateHCID 31268PyrrolidineHCID 69888694HCID 69888694, compound

Product 1

HCID 699464Ethyl 2-amino-1-benzothiophene-3-carboxylateYield 64%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 7947MesityleneSolvent

Procedure

2 g of palladium catalyst (5% Pd/C, approx. 50% moisture content; Degussa-Hüls; E 101 RW 5%) are added to a solution of 10 g of ethyl 2-acetylaminotetrahydrobenzothiophenecarboxylate in 80 ml of mesitylene and the mixture is heated to 170° under nitrogen. 2 g of ethyl cinnamate are metered in over 30 min and stirring is continued for 21 h. The temperature is then lowered to 100° and 10 ml of pyrrolidine are added. The reaction mixture is stirred for 25 h under nitrogen. The catalyst is then filtered off and rinsed with 60 g of ethanol. The solutions are combined and the solvent is distilled off. The residue is taken up in ethyl acetate and washed twice with 1 N HCl and once with water. After distillation of the solvent and subsequent crystallization from 2-propanol, ethyl 2-aminobenzo[b]thiophene-3-carboxylate is obtained with a yield of 64%.

Workup

  1. temperaturethe mixture is heated to 170° under nitrogen
  2. customare metered in over 30 min
  3. customis then lowered to 100°
  4. stirringThe reaction mixture is stirred for 25 h under nitrogen
  5. filtrationThe catalyst is then filtered off
  6. washrinsed with 60 g of ethanol
  7. distillationthe solvent is distilled off
  8. washwashed twice with 1 N HCl and once with water
  9. distillationAfter distillation of the solvent and subsequent crystallization from 2-propanol

Sources & evidence

ORD record
ord-b86474ad00ab4103848da13e27a905f7
Source dataset
uspto-grants-2004_04
Patent number
US06723848B2

Reaction notes

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