2-Amino-4-(4-aminophenyl)thiazole → 4-Amino-benzylidene-hydantoin

HRID 1637932Notes

Reaction equation

HRID 1637932 reaction equation
[N+:1]([C:4]1[CH:17]=[CH:16][C:7]([CH:8]=[C:9]2[NH:13][C:12](=[O:14])[NH:11][C:10]2=[O:15])=[CH:6][CH:5]=1)([O-])=O.NC1SC=C(C2C=CC(N)=CC=2)N=1>C(O)(=O)C.[Fe]>[NH2:1][C:4]1[CH:17]=[CH:16][C:7]([CH:8]=[C:9]2[NH:13][C:12](=[O:14])[NH:11][C:10]2=[O:15])=[CH:6][CH:5]=1

Participants

5

Reactant 2

HCID 6055642-Amino-4-(4-aminophenyl)thiazoleHCID 46859054-Nitro-benzylidene-hydantoin

Product 1

HCID 538516234-Amino-benzylidene-hydantoin

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 176Acetic AcidSolvent

Procedure

To 3 g (12.9 mmol) of crude 4-nitro-benzylidene-hydantoin, melting point 300° C. (prepared as described in Example 6 under (a)) in 50 ml 80% acetic acid are added 3 g of iron powder at 100°. After 30 minutes the mixture is filtered over kieselguhr and the filtrate is evaporated down in vacuo. The evaporation residue is divided between EtOac and dilute aqueous ammonia solution; before the separation of the phases the mixture is filtered once more through kieselguhr. The organic phase is washed with water, dried, filtered and evaporated down in vacuo. The yellow foam obtained (0.80 g; 30.6% of theory) predominantly contains 4-amino-benzylidene-hydantoin (A) (Rf =0.55), but no 4-amino-benzyl-hydantoin (B) (Rf =0.48), according to DC (silica gel; toluene/EtOac/EtOH (4:2:1)).

Workup

  1. filtrationAfter 30 minutes the mixture is filtered over kieselguhr
  2. customthe filtrate is evaporated down in vacuo
  3. custombefore the separation of the phases the mixture
  4. filtrationis filtered once more through kieselguhr
  5. washThe organic phase is washed with water
  6. customdried
  7. filtrationfiltered
  8. customevaporated down in vacuo

Sources & evidence

ORD record
ord-d71ca5a8497c40c99cb6f9c6366ccaa6
Source dataset
uspto-grants-2000_03
Patent number
US06043254

Reaction notes

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