N-bromobutanimide → 7-Bromo-4-phenyl-5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2(1H)-one

HRID 589092Notes

Reaction equation

HRID 589092 reaction equation
[C:1]1([CH:7]2[CH2:16][CH2:15][C:14]3[C:9]4=[C:10]([NH:17][C:18](=[O:19])[N:8]24)[CH:11]=[CH:12][CH:13]=3)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[Br:20]N1C(=O)CCC1=O>C(#N)C.C(O)(=O)C>[Br:20][C:13]1[CH:12]=[CH:11][C:10]2[NH:17][C:18](=[O:19])[N:8]3[C:9]=2[C:14]=1[CH2:15][CH2:16][CH:7]3[C:1]1[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 904094724-Phenyl-5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2(1H)-one

Product 1

HCID 904091427-Bromo-4-phenyl-5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2(1H)-oneYield 67.3%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 6342AcetonitrileSolvent2×

Conditions

Temperature
0 °C

Procedure

A suspension of 4-phenyl-5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2(1H)-one (0.200 g, 0.799 mmol) in acetonitrile (10.0 mL) and acetic acid (2.42 mL) was heated to dissolve residual solids and the resultant solution was cooled to 0° C. The resulting solution was treated with a solution of N-bromosuccinimide (0.144 g, 0.807 mmol) in acetonitrile (3.0 mL), added dropwise, at 0° C. and subsequently stirred at 0° C. for 1 h. The reaction mixture was concentrated to a residue which was dissolved in chloroform (50 mL) and washed with saturated aqueous sodium bicarbonate (40 mL) and brine (20 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated to give a crude solid. Purification by flash column chromatography (100% hexanes to 50% ethyl acetate/hexanes, the ethyl acetate containing 5% methanol) gave the desired product (0.177 g, 67%) as a racemic mixture along with an additional other brominated isomer, 8-bromo-4-phenyl-5,6-dihydro-4H-imidazo[4,5,1-ij]quinolin-2(1H)-one (which was not be separated) in a 4.4:1 ratio. LCMS calculated for C16H14BrN2O (M+H)+: m/z=329.0, 331.0. found: 329.0, 331.0.

Workup

  1. temperaturewas heated
  2. dissolutionto dissolve residual solids
  3. additionadded dropwise, at 0° C.
  4. concentrationThe reaction mixture was concentrated to a residue which
  5. dissolutionwas dissolved in chloroform (50 mL)
  6. washwashed with saturated aqueous sodium bicarbonate (40 mL) and brine (20 mL)
  7. dry with materialThe organic layer was dried over sodium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customto give a crude solid
  11. customPurification by flash column chromatography (100% hexanes to 50% ethyl acetate/hexanes

Sources & evidence

ORD record
ord-d9a36944598448bd82d3014c8eb1a4f9
Source dataset
uspto-grants-2016_01
Patent number
US09227985B2

Reaction notes

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