Ammonia → 7-Bromobenzothiazole-2,5-diamine

HRID 712157Notes

Reaction equation

HRID 712157 reaction equation
CCO.[Br:4][C:5]1[CH:10]=[C:9]([N+:11]([O-])=O)[CH:8]=[C:7]([N+:14]([O-])=O)[C:6]=1[S:17][C:18]#[N:19].Cl.N>[Fe].O>[Br:4][C:5]1[C:6]2[S:17][C:18]([NH2:19])=[N:14][C:7]=2[CH:8]=[C:9]([NH2:11])[CH:10]=1

Participants

7

Reactant 4

HCID 222AmmoniaHCID 313Hydrochloric AcidHCID 702EthanolHCID 86663954(2-Bromo-4,6-dinitro-phenyl) thiocyanate

Product 1

HCID 866639557-Bromobenzothiazole-2,5-diamineYield 93.2%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 962WaterSolvent

Procedure

To a stirred mixture of EtOH (8.37 L) and water (8.37 L) at rt was added (2-bromo-4,6-dinitro-phenyl)thiocyanate (549 g, 1.81 mol) followed by addition of Fe powder (2.02 kg, 36.11 mol) and drop wise addition of HCl (12N, 527 mL) over 30 min. The resulting reaction mixture was stirred at rt for 20 min then heated to 80° C. for 45 min. After completion of the reaction (by TLC) the reaction mixture was cooled to rt and basified to pH 8-10 by addition of aqueous ammonia solution. The resulting solution was passed through celite bed, washed with EtOAc and the combined filtrate evaporated under reduced pressure. To the resulting residue was added water (8 L) then extracted with EtOAc (2×4 L). The combined organics were washed with brine, dried (anhydrous Na2SO4), filtered and concentrated under reduced pressure to obtain the desired product (412 g, 93%). 1H NMR (DMSO-d6): δ 5.16 (br s, 2H), 6.50 (d, J=2.0 Hz, 1H), 6.53 (d, J=1.60 Hz, 1H) and 7.44 (br s, 2H). LCMS: 243.86 [M+H]+.

Workup

  1. customThe resulting reaction mixture
  2. temperaturethen heated to 80° C. for 45 min
  3. customAfter completion of the reaction (by TLC) the reaction mixture
  4. washwashed with EtOAc
  5. customthe combined filtrate evaporated under reduced pressure
  6. additionTo the resulting residue was added water (8 L)
  7. extractionthen extracted with EtOAc (2×4 L)
  8. washThe combined organics were washed with brine
  9. dry with materialdried (anhydrous Na2SO4)
  10. filtrationfiltered
  11. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-034913bfae864cb7a8656612de3c51c9
Source dataset
uspto-grants-2015_11
Patent number
US09181234B2

Reaction notes

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