[(2,4-Dinitrophenyl)thio]acetic acid → 6-amino-3,4-dihydro-2H-1,4-benzothiazin-3-one

HRID 1915381Notes

Reaction equation

HRID 1915381 reaction equation
[N+:1]([C:4]1[CH:9]=[C:8]([N+:10]([O-])=O)[CH:7]=[CH:6][C:5]=1[S:13][CH2:14][C:15]([OH:17])=O)([O-])=O.O.O.[Sn](Cl)Cl>C(O)C>[NH2:10][C:8]1[CH:7]=[CH:6][C:5]2[S:13][CH2:14][C:15](=[O:17])[NH:1][C:4]=2[CH:9]=1

Participants

4

Reactant 2

HCID 60055[(2,4-Dinitrophenyl)thio]acetic acidHCID 61436Stannous chloride dihydrate

Product 1

HCID 6869016-amino-3,4-dihydro-2H-1,4-benzothiazin-3-oneYield 61.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 2-(2,4-dinitrophenylthio)-acetic acid (2.3 g, 9 mmol) and tin (II) chloride dihydrate (22.6 g, 0.1 mol) in ethanol (30 mL) was refluxed overnight. After removal of the solvent under reduced pressure, the residual slurry was diluted with water (100 mL) and basified with 10% Na2CO3 solution to pH 8. The resulting suspension was extracted with ethyl acetate (3×100 mL). The ethyl acetate extract was washed with water and brine, dried over Na2SO4, and concentrated. The residue was washed with CH2Cl2 to yield 6-amino-2H-benzo[b][1,4]thiazin-3(4H)-one (DC-7) as a yellow powder (1 g, 52%). 1H NMR (DMSO-d6) δ 10.24 (s. 1H), 6.88 (d, 1H, J=6 Hz), 6.19-6.21 (m, 2H), 5.15 (s, 2H), 3.28 (s, 2H); ESI-MS 181.1 m/z (MH+).

Workup

  1. customAfter removal of the solvent under reduced pressure
  2. additionthe residual slurry was diluted with water (100 mL)
  3. extractionThe resulting suspension was extracted with ethyl acetate (3×100 mL)
  4. extractionThe ethyl acetate extract
  5. washwas washed with water and brine
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated
  8. washThe residue was washed with CH2Cl2

Sources & evidence

ORD record
ord-3b395da024e44dfea8894c52dff3391d
Source dataset
uspto-grants-2013_12
Patent number
US08614327B2

Reaction notes

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