Dimethylformamide → 4-Cyano-3-methyl-benzofuran-2-carboxylic acid ethyl ester

HRID 29283Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12](OS(C(F)(F)F)(=O)=O)[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2].[CH3:24][N:25](C=O)C>[C-]#N.[C-]#N.[Zn+2].C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([C:24]#[N:25])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2]

Participants

Conditions

Temperature: 85 °C

Procedure

To 3-methyl-4-trifluoromethanesulfonyloxy-benzofuran-2-carboxylic acid ethyl ester (721 mg, 2.0 mmol, 1 eq) in 10 mL of DMF under nitrogen was added 322 mg of Zn(CN)2 (2.74 mmol, 1.37 eq), and 123 mg of Pd(PPh3)4 (0.1 mmol, 0.05 eq). The reaction mixture was heated to 85° C. The reaction was complete in 2.5 h by TLC. After work up and column chromatography eluting with 5% ethyl acetate/hexane, 4-cyano-3-methyl-benzofuran-2-carboxylic acid ethyl ester was obtained in 80% yield (367 mg). 1H NMR (400 MHz, CD3OD) δ ppm 1.6 (t, J=7.1 Hz, 3 H) 3.0 (s, 3 H) 4.6 (q, J=7.2 Hz, 2 H) 7.8 (dd, J=8.3, 7.6 Hz, 1 H) 7.9(m, 1 H) 8.1 (dd, J=8.3, 1.0 Hz, 1 H).

Workup

washAfter work up and column chromatography eluting with 5% ethyl acetate/hexane

Sources & evidence

ORD record: ord-977eb97c13c140eb9d92d3966b22dbf2
Source dataset: uspto-grants-2008_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07420001B2

Reaction notes

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