3-Methyl-2-oxoimidazolidin-1-ylmethyl Polystyrene Resin cross-linked with 1% DVB

Experimental procedure: A mixture of 1 (984 mg) and oxalyl chloride (1.71 mmol) in benzene (10 mL) is refluxed for 24 h, cooled to room temperature and evaporated in vacuo to yield crude P-DMC (2, 1.19 g, 88% conversion).
  To a suspension of crude 2 (1.19 g), dihydrocinnamic acid (1.0 mmol) in CH₂Cl₂ (10 mL) are added tert-butyl alcohol (1.0 mmol) and Et₃N (5.0 mmol), and then the suspension is stirred at room temperature for 48 h. The polymer is recovered by filtration and washing with CH₂Cl₂. The filtrate and washings are combined, washed with 1 mol/L HCl, sat. NaHCO₃, H₂O and sat. NaCl, dried (over MgSO₄), and evaporated. Purification of the crude product by distillation (bp 110 °C/2.0 mmHg) yields the corresponding ester, 166 mg (80%), as a colorless oil. The recovered 1 is successively washed with 1 mol/L HCl, H₂O, methanol, and CH₂Cl₂, and dried at 40 °C.