2-(Ethoxymethylene)propanedinitrile → N-(1,3-Benzothiazol-5-yl)acetamide

HRID 2122012Notes

Reaction equation

HRID 2122012 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:9]=[CH:10][C:11]=1[SH:12])[NH:5][C:6](=[O:8])[CH3:7].[CH2:13](OC=C(C#N)C#N)C>CC(O)=O>[C:6]([NH:5][C:4]1[CH:9]=[CH:10][C:11]2[S:12][CH:13]=[N:1][C:2]=2[CH:3]=1)(=[O:8])[CH3:7]

Participants

4

Reactant 2

HCID 671522-(Ethoxymethylene)propanedinitrileHCID 21937579N-(3-Amino-4-sulfanylphenyl)acetamide

Product 1

HCID 285205N-(1,3-Benzothiazol-5-yl)acetamideYield 17%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
125 °C

Procedure

To a solution of intermediate 3′-amino-4′-mercaptoacetanilide in HOAc (50 mL) was added ethoxymethylene malononitrile (1.95 g, 16 mmol) and the resulting mixture was refluxed at 125° C. for 5 h. After cooling, the product mixture was concentrated under reduced pressure, and the residue was partitioned between satd aqueous NaHCO3 and EtOAc. The aqueous phase was extracted with EtOAc, and the combined extracts were washed with brine, dried over Na2SO4 and concentrated. The residue was purified by chromatography on silica gel, eluting with EtOAc-Hex (0:100 to 50:50) to give the title compound (508 mg, 17%) as a yellow solid. 1H-NMR (DMSO-d6): δ 9.35 (1H, s), 8.53(1H, s), 8.10 (1H, d), 7.63 (1H, d), 2.15 (3H, s).

Workup

  1. temperatureAfter cooling
  2. concentrationthe product mixture was concentrated under reduced pressure
  3. customthe residue was partitioned between satd aqueous NaHCO3 and EtOAc
  4. extractionThe aqueous phase was extracted with EtOAc
  5. washthe combined extracts were washed with brine
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated
  8. customThe residue was purified by chromatography on silica gel
  9. washeluting with EtOAc-Hex (0:100 to 50:50)

Sources & evidence

ORD record
ord-1a6402f15ebf4908b26dbc5c1c4eea82
Source dataset
uspto-grants-2004_02
Patent number
US06696473B2

Reaction notes

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