Benzo(d)thiazol-2-amine → HCID 3539255, compound

HRID 2351272Notes

Reaction equation

HRID 2351272 reaction equation
Cl[C:2](OC1C=CC([N+]([O-])=O)=CC=1)=[O:3].[NH2:14][C:15]1[S:16][C:17]2[CH:23]=[CH:22][CH:21]=[CH:20][C:18]=2[N:19]=1.[NH2:24][NH2:25]>C(Cl)(Cl)Cl.N1C=CC=CC=1>[S:16]1[C:17]2[CH:23]=[CH:22][CH:21]=[CH:20][C:18]=2[N:19]=[C:15]1[NH:14][C:2](=[O:3])[NH:24][NH2:25]

Participants

6

Reactant 3

HCID 8706Benzo(d)thiazol-2-amineHCID 9321HydrazineHCID 821294-Nitrophenyl chloroformate

Product 1

HCID 3539255HCID 3539255, compound

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 6212ChloroformSolvent

Conditions

Temperature
0 °C

Procedure

A solution of 4-nitrophenyl chloroformate, 5.04 g (25 mMole) in 25 ml of dry chloroform was added dropwise to a to a ice cooled, stirred solution of 2-aminobenzothiazole, 3.75 gm (25 mMole) in 50 ml of dry pyridine. The mixture was stirred at 0° C. for 45 minutes longer. Anhydrous hydrazine, 1.6 ml (250 mMole), was added rapidly to the stirred reaction mixture and the ice bath was removed. Stirring was continued for 3 hours at 22° C. Insolubles were filtered, rinsed with cold methanol and dissolved in dilute aqueous hydrochloric acid. Insolubles were filtered off and the aqueous solution was extracted with ethyl acetate. The aqueous solution was made basic, pH 9.5, by addition of aqueous sodium hydroxide. The insoluble product was filtered, washed with water, dried, and recrystallized from ethanol furnishing 1.35 g of 4-(benzothiazol-2-yl)-semicarbazide melting at 225° C. The product was characterized by nuclear magnetic resonance, mass spectra, infrared spectra and elemental analyses.

Workup

  1. temperaturecooled
  2. customthe ice bath was removed
  3. stirringStirring
  4. waitwas continued for 3 hours at 22° C
  5. filtrationInsolubles were filtered
  6. washrinsed with cold methanol
  7. dissolutiondissolved in dilute aqueous hydrochloric acid
  8. filtrationInsolubles were filtered off
  9. extractionthe aqueous solution was extracted with ethyl acetate
  10. additionpH 9.5, by addition of aqueous sodium hydroxide
  11. filtrationThe insoluble product was filtered
  12. washwashed with water
  13. customdried
  14. customrecrystallized from ethanol furnishing 1.35 g of 4-(benzothiazol-2-yl)-semicarbazide melting at 225° C

Sources & evidence

ORD record
ord-26c12397b2bc47a390ce2cd2ad095252
Source dataset
uspto-grants-1989_10
Patent number
US04873224

Reaction notes

Loading…