Method 1: 1.1 Step 1) 2-cyanoethyl acetoacetate 2,2,6-Trimethyl-4H-1,3-dioxan-4-one (15.50 g, 109.0 mmol), 3-hydroxypropionitrile (7.75 g, 109 mmol) and o-xylene (20 mL)The reaction was carried out at 141 ° C for 2 hours. Cool to room temperature,The solvent was evaporated to give a pale yellow oil (16.63 g, 98.30%).Method 2: 29 That is accurately weighed 1.42g 10mmol of 2,2,6-trimethyl-1,3-dioxin-4-one -4H and 0.82mL Approximately 12mmol of 2-hydroxy-acetonitrile, dissolved in 10mL of ethylene and heated to 140-145 ° C, The reaction was refluxed for 1h, cooled to room temperature, the solvent was removed by rotary evaporation and the residue was purified by flash column chromatography pure Of Compound S711.4g, 90% yield.
