Sodium Carbonate → 1-Ethyl-5-fluoro-1,3-dihydro-2,1-benzisothiazol-4-amine 2,2-dioxide

HRID 1289360Notes

Reaction equation

HRID 1289360 reaction equation
[CH2:1]([N:3]1[C:7]2[CH:8]=[CH:9][C:10]([F:15])=[C:11]([N+:12]([O-])=O)[C:6]=2[CH2:5][S:4]1(=[O:17])=[O:16])[CH3:2].Cl[Sn]Cl.O.C([O-])([O-])=O.[Na+].[Na+]>C(OCC)(=O)C>[CH2:1]([N:3]1[C:7]2=[CH:8][CH:9]=[C:10]([F:15])[C:11]([NH2:12])=[C:6]2[CH2:5][S:4]1(=[O:17])=[O:16])[CH3:2]

Participants

5

Reactant 3

HCID 10340Sodium CarbonateHCID 154053661-Ethyl-5-fluoro-1,3-dihydro-4-nitro-2,1-benzisothiazole 2,2-dioxideHCID 43835034Tin dichloride dihydrate

Product 1

HCID 154053671-Ethyl-5-fluoro-1,3-dihydro-2,1-benzisothiazol-4-amine 2,2-dioxideYield 74.3%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent2×

Procedure

A mixture of 1-ethyl-5-fluoro-1,3-dihydro-4-nitro-2,1-benzisothiazole 2,2-dioxide (1.0 g, 3.8 mmol) and SnCl2.H2O (4.34 g, 19.2 mmol) in ethyl acetate (50 mL) was heated at reflux for 3 h. After completion of the reaction based on thin layer chromatography, the mixture was diluted with ethyl acetate (100 mL) and solid Na2CO3 (12.5 g) was added. The resulting mixture was vigorously stirred for 12 h and then filtered through a pad of diatomaceous earth (Celite®). The filtrate was then evaporated under reduced pressure, and the residue was subjected to flash chromatography (silica gel, chlorobutane:ether 1:10 v/v) to give 650 mg of the title compound of Step D. 1H NMR (CDCl3, 400 MHz): δ6.94 (m,1H), 6.08 (m,1H), 4.10 (s,2H), 3.80 (br s,2H), 3.62 (q,2H), 1.36 (t,3H).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 3 h
  3. additionwas added
  4. filtrationfiltered through a pad of diatomaceous earth (Celite®)
  5. customThe filtrate was then evaporated under reduced pressure

Sources & evidence

ORD record
ord-bffcb68fef9f40a28e8c99d45fe1ed49
Source dataset
uspto-grants-1998_05
Patent number
US05750471

Reaction notes

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