Piperazine → 1-Benzothiophen-3-amine

HRID 1441728Notes

Reaction equation

HRID 1441728 reaction equation
COC([C:5]1[S:6][C:7]2[CH:14]=[CH:13][CH:12]=[CH:11][C:8]=2[C:9]=1[NH2:10])=O.N1CCNCC1>CN1CCCC1=O>[NH2:10][C:9]1[C:8]2[CH:11]=[CH:12][CH:13]=[CH:14][C:7]=2[S:6][CH:5]=1

Participants

4

Reactant 2

HCID 4837PiperazineHCID 874720Methyl 3-aminobenzo[b]thiophene-2-carboxylate

Product 1

HCID 111944231-Benzothiophen-3-amineYield 83.3%

Reagents, catalysts & solvents 1

HCID 13387N-methyl-2-pyrrolidoneSolvent

Procedure

A solution of methyl-3-aminobenzothiophene-2-carboxylate (1 g, 4.83 mmol, 1 eq) in 1-methyl-2-pyrrolidinone (8 mL) and piperazine (2.08 g, 24.13 mmol, 5 eq) was stirred at 130° C. overnight. Ice was added, and the mixture was extracted with EtOAc. The organic extracts were washed twice with water, dried, and concentrated in vacuo. The crude material was purified by flash chromatography on silica gel eluting with 33% ethyl acetate in hexanes to provide 600 mg (83%) of compound 39A as a yellow oil. HPLC: 98% at 1.043 min (retention time) (YMC S5 ODS 4.6×50 mm, 10-90% aqueous methanol over 4 minutes containing 0.2% phosphoric acid, monitoring at 220 nm).

Workup

  1. additionIce was added
  2. extractionthe mixture was extracted with EtOAc
  3. washThe organic extracts were washed twice with water
  4. customdried
  5. concentrationconcentrated in vacuo
  6. customThe crude material was purified by flash chromatography on silica gel eluting with 33% ethyl acetate in hexanes

Sources & evidence

ORD record
ord-5c15187c472349c5b833c80afaec3d99
Source dataset
uspto-grants-2010_02
Patent number
US07655688B2

Reaction notes

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