Ethyl Acetate → 4-Bromo-3-methylbenzene-1,2-diamine

HRID 475240Notes

Reaction equation

HRID 475240 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([N+:8]([O-])=O)=[C:4]([N+:11]([O-])=O)[C:3]=1[CH3:14].O.O.Cl[Sn]Cl.CCOC(C)=O.C([O-])(O)=O.[Na+]>CCO>[Br:1][C:2]1[C:3]([CH3:14])=[C:4]([NH2:11])[C:5]([NH2:8])=[CH:6][CH:7]=1

Participants

6

Reactant 4

HCID 8857Ethyl AcetateHCID 61436Stannous chloride dihydrateHCID 516892Sodium BicarbonateHCID 158896331-Bromo-2-methyl-3,4-dinitrobenzene

Product 1

HCID 592142734-Bromo-3-methylbenzene-1,2-diamineYield 91%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
80 °C

Procedure

A mixture of 154 (40 g, 154 mmol), SnCl2.2H2O (208 g, 920 mmol), EtOAc (300 mL) and EtOH (150 mL) was heated to 80° C. for 12 h, cooled to RT, poured into crushed ice (2 Kg) and the pH adjusted to pH 7-8 with solid NaHCO3. The solid was filtered and washed with EtOAc. The filtrate was thrice extracted with EtOAc. The combined extracts were washed with brine, dried (Na2SO4), filtered and concentrated in vacuo. The crude product was purified by SiO2 chromatography eluting with an EtOAc/hexane gradient (10 to 50% EtOAc) to afford 28 g (91%) of 4-bromo-3-methyl-1,2-benzenediamine (156) as a brown oil: MS (ESI) m/z=202 [M+1]+.

Workup

  1. temperaturecooled to RT
  2. additionpoured
  3. filtrationThe solid was filtered
  4. washwashed with EtOAc
  5. extractionextracted with EtOAc
  6. washThe combined extracts were washed with brine
  7. dry with materialdried (Na2SO4)
  8. filtrationfiltered
  9. concentrationconcentrated in vacuo
  10. customThe crude product was purified by SiO2 chromatography
  11. washeluting with an EtOAc/hexane gradient (10 to 50% EtOAc)

Sources & evidence

ORD record
ord-02213e6c94514f90846136c5d2d1d675
Source dataset
uspto-grants-2014_01
Patent number
US08637537B2

Reaction notes

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