Tetrabutylammonium → Methacrylic Acid

Beteiligte Stoffe

Reaktionsschritte

To a solution of 3.48 g (4.04 mL, 20 mmol) of 1-methoxy-1-trimethylsiloxy-2-methyl-1-propene and 0.2 mL of tetrabutylammonium biacetate hexahydrate (0.04 M in THF) in 30 mL of THF was added dropwise 15.9 g (18 mL, 100 mmol) of trimethylsilyl methacrylate. During the course of the addition the temperature of the reaction mixture rose slowly while four 0.2 mL portions of tetrabutylammonium biacetate hexahydrate (0.04 M in THF) were added. The temperature continued to rise to 44° C. after all of the monomer had been added. When the temperature began to fall, 50 mL of THF was added, and the addition of 38.1 g (37.7 mL, 200 mmol) of 2-phenylethyl methacrylate (purified by passage over a column of basic alumina under argon) was begun. When the addition was complete and the temperature began to fall, 24.6 g (24.6 mL, 100 mmol) of ethoxytriethylene glycol methacrylate (purified by passage over a column of basic alumina under argon) was added dropwise from an addition funnel. Analysis of an aliquot of the solution by 1H nmr showed that there was no residual monomer present. The solution of poly(trimethylsilyl methacrylate [25 mol %]-b-2-phenylethyl methacrylate [50 mol %]-b-ethoxytriethylene glycol methacrylate [25 mol%]) was refluxed for 12 hr with methanolic tetrabutylammonium fluoride. After evaporation in a rotary evaporator under reduced pressure, the residual polymer was dried for 48 hr in a vacuum oven at 80° C. to give 58 g of poly(methacrylic acid [25 mol %]-b 2-phenylethyl methacrylate [50 mol %]-b-ethoxytriethylene glycol methacrylate [25 mol %]). 1H NMR analysis of the product showed that no trimethylsilyl ester groups remained.

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