[OH:1][C:2]1[C:9]([N+:10]([O-:12])=[O:11])=[CH:8][C:5]([C:6]#[N:7])=[CH:4][C:3]=1I.C(=O)([O-])[O-].[K+].[K+].[C:20](B(O)O)([CH3:22])=[CH2:21]>O1CCOCC1.O.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[OH:1][C:2]1[C:3](/[CH:21]=[CH:20]/[CH3:22])=[CH:4][C:5]([C:6]#[N:7])=[CH:8][C:9]=1[N+:10]([O-:12])=[O:11]
To a solution of 2.61 g of 4-hydroxy-3-iodo-5-nitrobenzonitrile in 315 ml of dioxane and 18 ml of water was added potassium carbonate (2.49 g), isopropenyl boronic acid (3.09 g), and tris(dibenzylideneacetone)dipalladium(0) (824 mg). This mixture was heated to reflux for 72 h. LC/MS analysis of the crude reaction mixture showed formation of a ca. 1:1 mixture of the desired product and the isopropenyl isomer. The mixture was cooled to room temperature, acidified by addition of 10 ml of acetic acid, loaded onto a silica gel column, eluted with ethyl acetate, and concentrated in vacuo. The residue was dissolved in dichloromethane and a small amount of ethyl acetate and was purified by column chromatography (2×) on a Biotage Horizon instrument (65i column), eluting with 1 column volume of 100% hexanes followed by a gradient of 0-20% ethyl acetate in hexanes over 10 column volumes to provide the title compound (1.78 g, 97%) contaminated with a small amount of dibenzylideneacetone. Mass spectrum (ESI) 203.1 (M−1).
Wird geladen…
