Methyl Methacrylate → 1,2,2,3-Tetramethylpiperidine

Participants

Reaction Steps

An oven-dried, 3-neck, 250-mL flask equipped with mechanical stirrer, rubber septum inlet, thermometer, and an argon atmosphere was charged with tetrahydrofuran (THF) (100 mL, freshly distilled from lithium aluminum hydride) and 2,2,6,6-tetramethylpiperidine (1.69 mL, 0.01 mol, distilled from NaOH and stored over molecular sieves under argon). n-Butyllithium (6.25 mL of a 1.6M solution in hexane, 0.01 mol) was added to the solution at 23°-27°; the resulting solution was stirred 15 min and then cooled to below -70° in a dry ice-acetone bath. To this solution containing 2,2,6,6-tetramethylpiperidinyllithium was added dropwise methyl methacrylate (10.7 mL, 0.1 mol, filtered through 10 wt % neutral alumina) over 15 min at -78° to -70°. The solution was warmed and poured into water (1.5 L); the precipitated polymer was isolated and dried, and then taken up and precipitated into hexane (1.5 L) from an acetone (75 mL) solution. After drying, 10.1 g (88% yield) of tetramethylpiperidine-ended polymethyl methacrylate (PMMA) was recovered; GPC analysis showed: Mn 1400, Mw 1700 (mol wt 1140 by design).

Provenance & Evidence