1,8-Diazabicyclo(5.4.0)undec-7-ene → Ethyl 3-methyl-1H-pyrrole-2-carboxylate

HRID 1366938Notes

Reaction equation

HRID 1366938 reaction equation
[CH2:1]([O:3][C:4]([CH:6]1[C:10]([CH3:11])=[CH:9][CH2:8][N:7]1S(C1C=CC(C)=CC=1)(=O)=O)=[O:5])[CH3:2].C1CCN2C(=NCCC2)CC1>C1COCC1.CCOCC>[CH2:1]([O:3][C:4]([C:6]1[NH:7][CH:8]=[CH:9][C:10]=1[CH3:11])=[O:5])[CH3:2]

Participants

5

Reactant 2

HCID 811841,8-Diazabicyclo(5.4.0)undec-7-eneHCID 15747141Ethyl 3-methyl-1-(4-methylphenyl)sulfonyl-2,5-dihydropyrrole-2-carboxylate

Product 1

HCID 5324582Ethyl 3-methyl-1H-pyrrole-2-carboxylateYield 98.6%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

Pyrroline 83 (8.80 g, 28.48 mmol) was dissolved in THF (70 mL). DBU (9.78 mL, 65.50 mmol) was added dropwise and the resulting solution stirred under reflux overnight. The mixture was cooled to room temperature, diluted with ether and washed with 5% aq. HCl, 5% sodium bicarbonate solution and water. The organic layer was dried over sodium sulfate, filtered and evaporated under reduced pressure to give the crude solid 84 (4.30 g, 98%). 1H-NMR (400 MHz, CDCl3): δ 1.37 (t, 3H), 2.35 (s, 3H), 4.31 (q, 2H), 6.08 (d, 1H), 6.81 (d, 1H), 8.90 (s broad, 1H) ppm. 13C-NMR (100 MHz, CDCl3): δ □ 12.76, 14.53, 59.96, 112.58□, 119.35, 121.53, 127.96, 162.01 ppm. DEPT (100 MHz, CDCl3): CH3 carbons: 12.76, 14.53; CH2 carbons: 59.96; CH carbons: 112.58, 121.53 ppm. LC/MS: 90.74%, m/z=153.

Workup

  1. temperatureunder reflux overnight
  2. washwashed with 5% aq. HCl, 5% sodium bicarbonate solution and water
  3. dry with materialThe organic layer was dried over sodium sulfate
  4. filtrationfiltered
  5. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-8b771e840c30406988ef2c69d1611917
Source dataset
uspto-grants-2011_02
Patent number
US07893098B2

Reaction notes

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