To N-[(3S)-Pyrrolidin-3-yl]quinolin-4-amine (32 mg, 0.15 mmol) dissolved in 1.5 ml anhydrous dichloromethane triethylamine (0.9 mmol, 91 mg) was added with stirring followed by (E)-4-methylpent-2-enoyl chloride dissolved in anhydrous dichloromethane (29.8 mg, 0.23 mmol). The mixture was stirred at room temperature for 5 minutes after which polymer-supported toluenesulfonyl chloride (600 mg, 1-2 mmol/g) was added and the mixture was shaken for 15 minutes, filtered and the filtrate evaporated to dryness under reduced pressure. The raw product was purified by preparative HPLC (gradient of water containing 0.1% ammonia and acetonitrile) to yield 18 mg of a solid (0.58 mmol, 39%).
