Iodine → Methyl 4-formyl-5-iodo-1H-pyrrole-2-carboxylate

HRID 1952536Notes

Reaction equation

HRID 1952536 reaction equation
[CH:1]([C:3]1[CH:4]=[C:5]([C:8]([O:10][CH3:11])=[O:9])[NH:6][CH:7]=1)=[O:2].[I:12]I>C(Cl)(Cl)Cl>[CH:1]([C:3]1[CH:4]=[C:5]([C:8]([O:10][CH3:11])=[O:9])[NH:6][C:7]=1[I:12])=[O:2]

Participants

4

Reactant 2

HCID 807IodineHCID 640310methyl 4-formyl-1H-pyrrole-2-carboxylate

Product 1

HCID 86664848Methyl 4-formyl-5-iodo-1H-pyrrole-2-carboxylate

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

To a stirred solution of 3 (3.40 g, 22.2 mmol) in CHCl3 (20 mL) at 0° C. was added CF3COOAg (5.40 g, 24.4 mmol) followed by I2 (3.10 g, 24.4 mmol). The resulting mixture was stirred for 16 hours in the dark at room temperature. The reaction mixture was filtered through Celite and the filtrate was washed with saturated aqueous solution of Na2S2O3 (2×20 mL). The organic layer was dried over anhydrous MgSO4, filtered and concentrated in vacuo. MPLC purification (CH2Cl2:diethyl ether/95:5) of the residue gave 4 as a white solid (0.72 g, 32% based on the recovered starting material). Along with 4, two minor compounds methyl-4-formyl-5-iodo-1H-pyrrole-2-carboxylate, methyl 4-formyl-3,5-diiodo-1H-pyrrole-2-carboxylate and the starting material 3 were also isolated. 1H NMR (DMSO-d6) δ 13.30 (bs, 1H), 9.52 (s, 1H), 7.04 (s, 1H), and 3.77 (s, 3H); 13C NMR (DMSO-d6) δ 187.13, 160.36, 128.78, 127.79, 115.58, 87.40, and 52.42.

Workup

  1. filtrationThe reaction mixture was filtered through Celite
  2. washthe filtrate was washed with saturated aqueous solution of Na2S2O3 (2×20 mL)
  3. dry with materialThe organic layer was dried over anhydrous MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customMPLC purification (CH2Cl2:diethyl ether/95:5) of the residue

Sources & evidence

ORD record
ord-c310c0ed63284298b58b0d5d7e2dfdca
Source dataset
uspto-grants-2013_03
Patent number
US08404728B2

Reaction notes

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