6-Nitro-2H-1,4-benzoxazin-3(4H)-one → 6-amino-3,4-dihydro-2H-1,4-benzoxazin-3-one

HRID 221213

Reaction equation

HRID 221213 reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[O:12][CH2:11][C:10](=[O:13])[NH:9][C:8]=2[CH:14]=1)([O-])=O.[BH4-].[K+].[H][H]>CO.Cl[Cu]>[NH2:1][C:4]1[CH:5]=[CH:6][C:7]2[O:12][CH2:11][C:10](=[O:13])[NH:9][C:8]=2[CH:14]=1

Participants

6

Reactant 3

HCID 27636836-Nitro-2H-1,4-benzoxazin-3(4H)-oneHCID 4192641Potassium borohydrideHCID 178418361HCID 178418361, compound

Product 1

HCID 27636816-amino-3,4-dihydro-2H-1,4-benzoxazin-3-one

Reagents, catalysts & solvents 2

HCID 62652Cuprous chlorideCatalystHCID 887MethanolSolvent

Conditions

Temperature
25 °C

Procedure

To a suspension of 6-nitro-2H-1,4-benzoxazin-3(4H)-one 1 (0.5 g, 0.0026 mol) and CuCl (0.77 g, 0.0078 mol) in anhydrous methanol (25 mL), stirred at 25° C. was added potassium borohydride (0.98 g, 0.018 mol) in portions (exothermic with evolution of hydrogen gas). The reaction mixture was stirred at 25° C. for 30 min. The black precipitate formed was filtered and washed with methanol. The combined filtrate and washings was evaporated to give 6-amino-2H-benzo[b][1,4]oxazin-3(4H)-one which was purified by silica gel column chromatography using ethyl acetate. Brown solid (0.29 g, 67%). 1H NMR (400 MHz, CDCl3): δ 4.34 (s, 2H); 4.81 (s, 2H); 6.09 (dd, J=2.8, 8.4 Hz, 1H); 6.14 (d, J=2.8 Hz, 1H); 6.59 (d, J=8.4 Hz, 1H); 10.44 (s, 1H).

Workup

  1. stirringThe reaction mixture was stirred at 25° C. for 30 min
  2. customThe black precipitate formed
  3. filtrationwas filtered
  4. washwashed with methanol
  5. customThe combined filtrate and washings was evaporated

Sources & evidence

ORD record
ord-2e98c9e1ed584d54ad37a534d8fce68c
Source dataset
uspto-grants-2012_06
Patent number
US08207163B2

Linked notes

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