Hydrochloric Acid → 7-Methoxy-8-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-one

HRID 515729

Reaction equation

HRID 515729 reaction equation
[CH3:1][O:2][C:3]1[C:4]([CH3:17])=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][C:7]([C:12]([O:14]CC)=O)=[CH:6]2.[CH3:18][C:19]([O-])(C)C.[K+].C1COCC1.C(OC)(=O)C=C.Cl>C1(C)C=CC=CC=1>[CH3:1][O:2][C:3]1[CH:11]=[CH:10][C:9]2[N:8]3[CH2:18][CH2:19][C:12](=[O:14])[C:7]3=[CH:6][C:5]=2[C:4]=1[CH3:17]

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 7294Methyl AcrylateHCID 8028TetrahydrofuranHCID 21396313ethyl 5-methoxy-4-methyl-1H-indole-2-carboxylateHCID 23665647Potassium tert-butoxide

Product 1

HCID 672497037-Methoxy-8-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-one

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

To a suspension of ethyl 5-methoxy-4-methyl-1H-indole-2-carboxylate (712 mg, 3.05 mmol) in toluene (10 mL) was added a 1 M solution of KOtBu in THF (3.97 mL, 3.97 mmol). The reaction mixture was stirred at room temperature for 5 min, methyl acrylate (825 μL, 9.15 mmol) was added. The reaction was stirred at reflux overnight and neutralized with 1 N HCl aqueous solution. The solid was collected and divided into three microwave vial. Each was added AcOH (8 mL) and H2O (1 mL), and heated at 180° C. for 15 min under microwave irradiation. The solvent was evaporated and the residue was purified by silica gel column chromatography to give the title compound as a yellow solid (500 mg). LCMS m/z=216.2 [M+H]+; 1H NMR (400 MHz, CDCl3) δ ppm 2.45 (s, 3H), 3.21 (t, J=6.5 Hz, 2H), 3.68 (s, 3H), 4.40 (t, J=6.2 Hz, 2H), 6.98 (s, 1H), 7.13 (d, J=9.0 Hz, 1H), 7.23 (d, J=9.0 Hz, 1H).

Workup

  1. stirringThe reaction was stirred
  2. customThe solid was collected
  3. additionEach was added AcOH (8 mL) and H2O (1 mL)
  4. temperatureheated at 180° C. for 15 min under microwave irradiation
  5. customThe solvent was evaporated
  6. customthe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-9662b9e604d14456a6dddab211201da2
Source dataset
uspto-grants-2015_08
Patent number
US09108969B2

Linked notes

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