1. 芳环引入醛基
收率不错。
2. Rieche 甲酰化--吡咯环的选择性
看出Rieche甲酰化比Vilsmeier甲酰化反应有更好的选择性
2,4,6-Trimethylbenzaldehyde (3).3 2 (30 mL, 0.33 mol) and 1 (23 mL, 0.17 mol) in DCM (100 mL) was added at 25 ℃ over 5 min to TiCl4 (73 mL, 0.67 mol) in DCM (150 mL). After 15 min stirring, ice (500 g) was added. Extraction with DCM, washing and distillation afforded 20.6 g of 3 (84%), bp 108–111 ℃/10 mm.
【Tetrahedron 1993, 49, 3397】
