Iodine → 3-(3,7-Dimethyloctyloxy)-phenylboric acid

Participants

Reaction Steps

After the heating, it was standing to cool to a room temperature. The reaction liquid was divided into two portions, each of which was added into 500 ml of water, and ethanol was distilled off with using evaporator. After distilling off the ethanol, the residual solutions were collected together and into three portions. To each of the portions, 300 ml of ethyl acetate was added and partitioned, respectively, and the organic layer was washed with 200 ml of water twice. After having collected the organic layers and distilling off the solvent using an evaporator, drying was carried out at 90° C. for 5 hours under reduced pressure using a rotary pump. About 150 g of 3-(3,7-dimethyloctyloxy)-bromobenzene was obtained as an oily product. Dried tetrahydrofuran 100 ml, magnesium 7.5 g and small quantity of iodine were charged into a three-necked flask under an inert atmosphere. Using a dropping funnel, the above 3-(3,7-dimethyloctyloxy)-bromobenzene 90 g was added dropwise for 50 minutes. After the dropwise adding, dried tetrahydrofuran 200 ml was added and heat-stirring was carried out for 2 hours with refluxing to prepare a Grignard reagent. After the heating, it was left standing to cool to a room temperature. Trimethyl borate 38 g and dried tetrahydrofuran 300 ml were charged into another three-necked flask, and the flask was cooled by a dry ice-acetone bath. Using a dropping funnel, the above Grignard reagent solution was added dropwise for 35 minutes. After the dropwise adding the reaction liquid was heated to a room temperature. After having added the reaction liquid to a dilute sulfuric acid (sulfuric acid 12 ml/water 360 ml) and stirring, it was divided into two portions, and each of them was extracted with 150 ml and 100 ml of ethyl acetate. The organic layers were collected together and divided into three portions, and each of them was washed with 100 ml of water. The organic layers after washing were collected together and the solvent was distilled off using an evaporator. A suspension of the solid content was produced by adding 100 ml of hexane and filtrated. Further, it washed with 100 ml of hexane. White solid of 3-(3,7-dimethyloctyloxy)-phenyl boric acid 63 g was obtained. Under an inert atmosphere, to a three-necked flask, the above 3-(3,7-dimethyloctyloxy)-bromobenzene 60 g, toluene 250 ml, water 250 ml, potassium carbonate 62 g and tetrakis (triphenylphosphine)palladium complex 1.2 g were charged. After bubbling of the solution with argon for 20 minutes to deaerate oxygen, the above 3-(3,7-dimethyloctyloxy)-phenyl boric acid 63 g was added, the temperature was raised to 90° C., and stirring with heating was carried out for 8 hours. After the heating, it was left to stand for cooling to a room temperature. After partitioning the toluene layer, coloring components were removed with silica gel chromatography. The solvent was distilled off and 98 g of Compound D was obtained as an oily product.

Provenance & Evidence