Boron tribromide → ethyl 2-(7-hydroxy-8-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate

HRID 515732Notes

Reaction equation

HRID 515732 reaction equation
C[O:2][C:3]1[CH:11]=[CH:10][C:9]2[N:8]3[CH2:12][CH2:13][CH:14]([CH2:15][C:16]([O:18][CH2:19][CH3:20])=[O:17])[C:7]3=[CH:6][C:5]=2[C:4]=1[CH3:21].B(Br)(Br)Br.C([O-])(O)=O.[Na+]>C(Cl)Cl>[OH:2][C:3]1[CH:11]=[CH:10][C:9]2[N:8]3[CH2:12][CH2:13][CH:14]([CH2:15][C:16]([O:18][CH2:19][CH3:20])=[O:17])[C:7]3=[CH:6][C:5]=2[C:4]=1[CH3:21]

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 516892Sodium BicarbonateHCID 67249023ethyl 2-(7-methoxy-8-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate

Product 1

HCID 67249573ethyl 2-(7-hydroxy-8-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetateYield 65.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred solution of ethyl 2-(7-methoxy-8-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-yl)acetate (320 mg, 1.114 mmol) in anhydrous DCM (8 mL) was added a 1M solution of boron tribromide in DCM (3341 μL, 3.34 mmol) at 0° C. under nitrogen protection. The reaction mixture was stirred at this temperature for 1 h, neutralized by addition of saturated NaHCO3 solution. The organic layer was separated and washed with water and dried over anhydrous Na2SO4. The solvent was evaporated, and the residue was purified by column chromatography to give the title compound (200 mg) as a light yellow oil. LCMS m/z=274.3 [M+H]+; 1H NMR (400 MHz, CDCl3) δ ppm 1.32 (t, J=7.1 Hz, 3H), 2.25-2.32 (m, 1H), 2.40 (s, 3H), 2.58 (dd, J=16.0, 8.5 Hz, 1H), 2.82-2.90 (m, 2H), 3.73-3.80 (m, 1H), 3.95-4.02 (m, 1H), 4.05-4.13 (m, 1H), 4.20-4.27 (m, 2H), 4.58 (s, 1H), 6.09 (s, 1H), 6.69 (d, J=8.5 Hz, 1H), 6.95 (d, J=8.5 Hz, 1H).

Workup

  1. customThe organic layer was separated
  2. washwashed with water
  3. dry with materialdried over anhydrous Na2SO4
  4. customThe solvent was evaporated
  5. customthe residue was purified by column chromatography

Sources & evidence

ORD record
ord-c73307463ac84442bf09f56ad3a92665
Source dataset
uspto-grants-2015_08
Patent number
US09108969B2

Reaction notes

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