Methanol → cis-5-Norbornene-endo-2,3-dicarboxylic acid monomethyl ester

HRID 548297

Reaction equation

HRID 548297 reaction equation
[CH2:1]1[C@@H:5]2[CH:6]3[C:11](=[O:12])[O:10][C:8](=[O:9])[CH:7]3[C@H:2]1[CH:3]=[CH:4]2.C1(C)C=CC=CC=1.COC1C=CC2N=CC=C([C@H](O)[C@@H]3N4C[C@H](C=C)C(CC4)C3)C=2C=1.[CH3:44][OH:45]>C(Cl)(Cl)(Cl)Cl>[CH3:44][O:45][C:11]([C@H:6]1[C@@H:5]2[CH2:1][C@@H:2]([CH:3]=[CH:4]2)[C@H:7]1[C:8]([OH:10])=[O:9])=[O:12]

Participants

6

Reactant 4

HCID 887MethanolHCID 1140TolueneHCID 5953(S)-[(2R,5R)-5-ethenyl-1-azabicyclo[2.2.2]octan-2-yl]-(6-methoxyquinolin-4-yl)methanolHCID 9964188cis-5-Norbornene-endo-2,3-dicarboxylic anhydride

Product 1

HCID 11435525cis-5-Norbornene-endo-2,3-dicarboxylic acid monomethyl esterYield 94%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Conditions

Temperature
-55 °C

Procedure

The starting material (a) was prepared as described in J. Org. Chem. 2000, 65, 6984-6991. cis-5-Norbornene-endo-2,3-dicarboxylic anhydride (8.21 g, 50 mmol) was suspended in a 1:1 mixture of toluene and carbon tetrachloride (250 mL). The mixture was stirred for 10 min. Quinidine (17.84 g, 55 mmol) was added and the flask was degassed and backfilled with nitrogen. The solution was cooled to −55° C. While stirring, methanol (6.08 mL, 150 mmol) was added. The mixture was stirred at −55° C. for 18 h. Upon warming to 25° C., the mixture was concentrated in vacuo to a thick oil. The oil was dissolved in a mixture of ethyl acetate (400 mL) and 1.0 M aqueous hydrochloric acid solution (300 mL). After shaking, the layers were separated and the organic layer was further washed with 1.0 M aqueous hydrochloric acid solution (2×100 mL), saturated aqueous brine solution (100 mL), dried over magnesium sulfate, filtered, and concentrated in vacuo to afford the desired product, (1S,2R,3S,4R)-3-(methoxycarbonyl)bicyclo[2.2.1]hept-5-ene-2-carboxylic acid (9.15 g, 46.6 mmol, 94%), as a clear oil. 1H NMR (400 MHz, DMSO-d6) δ: 1.26 (1H, d, J=8.4 Hz), 1.33 (1H, d, J=8.4 Hz), 3.00 (1H, s), 3.03 (1H, s), 3.21-3.29 (2H, m), 3.45 (3H, s), 6.02-6.04 (1H, m), 6.14-6.16 (1H, m), 11.86 (1H, s).

Workup

  1. customthe flask was degassed
  2. stirringWhile stirring
  3. stirringThe mixture was stirred at −55° C. for 18 h
  4. temperatureUpon warming to 25° C.
  5. concentrationthe mixture was concentrated in vacuo to a thick oil
  6. dissolutionThe oil was dissolved in a mixture of ethyl acetate (400 mL) and 1.0 M aqueous hydrochloric acid solution (300 mL)
  7. stirringAfter shaking
  8. customthe layers were separated
  9. washthe organic layer was further washed with 1.0 M aqueous hydrochloric acid solution (2×100 mL), saturated aqueous brine solution (100 mL)
  10. dry with materialdried over magnesium sulfate
  11. filtrationfiltered
  12. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-3a0cfe5e01764ec1a31508c08460eda1
Source dataset
uspto-grants-2011_05
Patent number
US07939524B2

Linked notes

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