Chloroform → (+/-)-6-Fluoro-8-amino-2,3-dihydrospiro[4H-1-benzopyran-4,5'-thiazolidine]-2',4'-dione

HRID 279877Notes

Reaction equation

HRID 279877 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([N+:18]([O-])=O)[C:5]2[O:17][CH2:16][CH2:15][C:8]3([S:12][C:11](=[O:13])[NH:10][C:9]3=[O:14])[C:6]=2[CH:7]=1.C(Cl)(Cl)Cl>C(O)C.[Pt]=O>[F:1][C:2]1[CH:3]=[C:4]([NH2:18])[C:5]2[O:17][CH2:16][CH2:15][C:8]3([S:12][C:11](=[O:13])[NH:10][C:9]3=[O:14])[C:6]=2[CH:7]=1

Participants

5

Reactant 2

HCID 6212ChloroformHCID 13998517(+/-)-6-fluoro-8-nitro-2,3-dihydrospiro[4H-1-benzopyran-4,5'-thiazolidine]-2',4'-dione

Product 1

HCID 13998518(+/-)-6-Fluoro-8-amino-2,3-dihydrospiro[4H-1-benzopyran-4,5'-thiazolidine]-2',4'-dione

Reagents, catalysts & solvents 2

HCID 82844Platinum oxide (PtO)Catalyst2×HCID 702EthanolSolvent

Procedure

755 mg of (±)-6-fluoro-8-nitro-2,3-dihydrospiro[4H-1-benzopyran-4,5'-thiazolidine]-2',4'-dione were hydrogenated at room temperature and normal pressure in the presence of 50 mg of platinum oxide in 50 ml of ethanol. An additional 100 mg of platinum oxide were added after 30 minutes. After 2.5 hours under hydrogen, some chloroform was added, the catalyst was filtered, the filtrate was concentrated and the residue was chromatographed on silica gel 60 with chloroform/methanol (19:1). (±)-6-Fluoro-8-amino-2,3-dihydrospiro[4H-1-benzopyran-4,5'-thiazolidine]-2',4'-dione was obtained in the form of a yellowish foam. The IR spectrum showed amine bands at 3383, 3202 and 2766 cm-1, in the mass spectrum the molecular ion appeared as a basic peak (m/e=268).

Workup

  1. customwere hydrogenated at room temperature
  2. filtrationthe catalyst was filtered
  3. concentrationthe filtrate was concentrated
  4. customthe residue was chromatographed on silica gel 60 with chloroform/methanol (19:1)

Sources & evidence

ORD record
ord-a831adcd33fc473cbbe22694fcff8ece
Source dataset
uspto-grants-1986_05
Patent number
US04587256

Reaction notes

Loading…