Magnesium Chloride → Ethyl 5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinoline-1-carboxylate

HRID 63548

Reaction equation

HRID 63548 reaction equation
[Cl-].[Mg+2].[Cl-].[CH2:4]([O:6][C:7](=[O:21])[C:8](=O)[CH2:9][N:10]1[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[CH2:13][CH2:12][CH2:11]1)[CH3:5]>COCCO>[CH2:4]([O:6][C:7]([C:8]1[C:18]2=[C:19]3[C:14](=[CH:15][CH:16]=[CH:17]2)[CH2:13][CH2:12][CH2:11][N:10]3[CH:9]=1)=[O:21])[CH3:5]

Participants

4

Reactant 2

HCID 5360315Magnesium ChlorideHCID 20729419ethyl 3-(3,4-dihydroquinolin-1(2H)-yl)-2-oxopropanoate

Product 1

HCID 20729414Ethyl 5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinoline-1-carboxylateYield 47%

Reagents, catalysts & solvents 1

HCID 80192-MethoxyethanolSolvent2×

Conditions

Temperature
125 °C

Procedure

Anhydrous magnesium chloride (29.4 g, 0.31 mol) was suspended in 2-methoxyethanol (400 mil), and the mixture was stirred for 15 minutes at 125° C. A solution of 3-(3,4-dihydro-2H-quinolin-1-yl)-2-oxopropionic acid ethyl ester (76.57 g 0.31 mol) in 2-methoxyethanol (100 ml) was then added and the mixture stirred at 125° C. for 60 minutes. The mixture was stirred for a further 5 hours at reflux, cooled and evaporated to dryness. The residue was then acidified with 2 M hydrochloric acid (500 ml) and extracted with dichloromethane (3×500 ml). The combined organic layers were then washed with 5% sodium bicarbonate solution and dried over anhydrous magnesium sulfate before being evaporated to dryness. The residue was then purified on a silica gel chromatography column, eluting with ethyl acetate/hexanes (1:4) to provide 5,6-dihydro-4H-pyrrolo[3,2,1-ij]quinoline-1-carboxylic acid ethyl ester (31.0 g, 47%). 1H NMR (CDCl3) 400 MHz δ: 7.9 (d, 1H, J=8 Hz), 7.79 (s, 1H), 7.17 (m, 1H), 6.99 (d, 1H, J=7.2 Hz), 4.37 (m, 2H), 4.18 (t, 2H, J=5.6 Hz), 3.0 (t, 2H, J=6 Hz), 2.24 (t, 2H, J=6 Hz), 1.42 (t, 3H, J=7.2 Hz).

Workup

  1. stirringthe mixture stirred at 125° C. for 60 minutes
  2. stirringThe mixture was stirred for a further 5 hours
  3. temperatureat reflux
  4. temperaturecooled
  5. customevaporated to dryness
  6. extractionextracted with dichloromethane (3×500 ml)
  7. washThe combined organic layers were then washed with 5% sodium bicarbonate solution
  8. dry with materialdried over anhydrous magnesium sulfate
  9. custombefore being evaporated to dryness
  10. customThe residue was then purified on a silica gel chromatography column
  11. washeluting with ethyl acetate/hexanes (1:4)

Sources & evidence

ORD record
ord-b896aae2747449809b82ec8a8c25a85b
Source dataset
uspto-grants-2016_09
Patent number
US09447088B2

Linked notes

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