Dimethylformamide → Ethyl-4-iodo-1H-pyrrole-2-carboxylic acid ethyl ester
Reaction equation
ClC(Cl)(Cl)[C:3]([C:5]1[NH:6][CH:7]=[C:8]([I:10])[CH:9]=1)=[O:4].[C:13]([O-:16])([O-])=O.[Cs+].[Cs+].I[CH2:20][CH3:21].[CH3:22]N(C=O)C>>[CH2:13]([O:16][C:3]([C:5]1[N:6]([CH2:20][CH3:21])[CH:7]=[C:8]([I:10])[CH:9]=1)=[O:4])[CH3:22]Participants
Procedure
Under a nitrogen atmosphere to a solution of 2,2,2-trichloro-1 (4-iodo-1H-pyrrol-2-yl)ethanone (9 g, 26.6 mmol) in DMF (30 mL) was added Cs2CO3 (17.4 g, 53.2 mmol) and stirred for 10 minutes. To this was then added a solution of iodoethane (8.72 g, 55.86 mmol) in DMF (10 mL). The new mixture was stirred at room temperature for 20 hours. A worked up TLC sample indicated the reaction was complete. DMF was removed in vacuo and the residue was taken back in a mixture of saturated aqueous NH4Cl: H2O (1:1, 200 mL) solution and extracted with ether. The combined ether extracts were washed with 5% Na2S2O5, dried (MgSO4) and filtered. Evaporation and purification by flash chromatography (hexane/ethyl acetate 9.7/0.3) gave light yellow oil (7 g, 89% yield), 1H NMR (400 MHZ, CDCl3) δ 1.3 (t, 3H), 1.35 (t, 3H), 4.22 (q 2H), 4.3 (q, 2H), 6.85 (s, 1H), 7.0 (s, 1H), MS m/e (M)+ 293.
Workup
- stirringThe new mixture was stirred at room temperature for 20 hours
- customDMF was removed in vacuo
- additionthe residue was taken back in a mixture of saturated aqueous NH4Cl: H2O (1:1, 200 mL) solution
- extractionextracted with ether
- washThe combined ether extracts were washed with 5% Na2S2O5
- dry with materialdried (MgSO4)
- filtrationfiltered
- customEvaporation and purification by flash chromatography (hexane/ethyl acetate 9.7/0.3)
Sources & evidence
- ORD record
- ord-c5f29999bf7a45629b225934cbe9e9ea
- Source dataset
- uspto-grants-2008_08
- Patent number
- US07417047B2
Reaction notes
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