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

HRID 1727622Notes

Reaction equation

HRID 1727622 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-d110626670f948c88e38b9a5f397366e
Source dataset
uspto-grants-2009_02
Patent number
US07495103B2

Reaction notes

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