1,4-Dibromobutane → 3-Methyl-4-pyrrolidin-1-yl-benzofuran-2-carboxylic acid ethyl ester
Reaction equation
[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([NH2:16])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2].Br[CH2:18][CH2:19][CH2:20][CH2:21]Br.C(N(CC)C(C)C)(C)C>C1(C)C=CC=CC=1>[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([N:16]3[CH2:21][CH2:20][CH2:19][CH2:18]3)[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2]Participants
5
Conditions
- Temperature
- 110 °C
Procedure
To 4-amino-3-methyl-benzofuran-2-carboxylic acid ethyl ester (500 mg, 2.28 mmol, 1 eq., prepared according to Example 60, Step 1) were added toluene (3 mL), 1,4-dibromobutane(272 uL, 2.28 mmol, 1 eq.), and N,N-diisopropylethylamine (953 uL, 5.47 mmol, 2.4 eq.) under argon in a sealed tube and the mixture was heated at 110° C. for 16 hours. After work-up and flash column chromatography, 3-methyl-4-pyrrolidin-1-yl-benzofuran-2-carboxylic acid ethyl ester was obtained in 48% yield. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.3 (t, J=7.1 Hz, 3 H) 1.9 (m, 4 H) 2.7 (s, 3 H) 3.1 (m, 4 H) 4.3 (q, J=7.1 Hz, 2 H) 6.8 (dd, J=8.0, 0.6 Hz, 1 H) 7.2 (dd, J=8.3, 0.8 Hz, 1 H) 7.3 (m, 1 H).
Sources & evidence
- ORD record
- ord-346b94f52ad74c85a1e4fbe1ab100a25
- Source dataset
- uspto-grants-2008_09
- Patent number
- US07420001B2
Reaction notes
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