反应详情

According to the procedure given for the synthesis of 202, ethyl p-tolylacetate (2.72 g, 15.2 mmol) was reacted with LDA (7.6 mL, 15.25 mmol) and methyl iodide (3.03 g, 21.30 mmol) in anhydrous THF (70 mL) and DMPU (1 mL). After aqueous workup and extraction, the residue was distilled in high vacuo to give 203 (2.5 g, 86.0%) as an oil. Bp 59-63° C./0.2 mmHg. 1H NMR (CDCl3): δ (ppm) 7.18 (d, 2 H, J=8.1), 7.10 (d, 2 H, J=8.1), 4.09 (m, 2 H), 3.67 (q, 1 H, J=7.2), 2.29 (s, 3 H), 1.47 (d, J=7.2 Hz, 3 H), 1.20 (t, J=5.7 Hz, 3 H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm) 174.71, 137.80, 136.63, 129.33, 129.14, 127.36, 60.66, 45.18, 21.05, 18.70, 14.15.

1. extractionAfter aqueous workup and extraction
2. distillationthe residue was distilled in high vacuo