反应 #1519159

反应方程式

4-bromo-1-tert-butoxycarbonyl-2-(3,4,5-trimethoxyphenyl)-pyrrole

pyridine-3-boronic acid

→

1-tert-butoxycarbonyl-4-(3-pyridyl)-2-(3,4,5-trimethoxy-phenyl)-pyrrole

收率 13.6%

反应条件

后处理

1. 1
   其他are evacuated for 10 min
2. 2
   workup.ADDITIONfollowed by addition of degassed dimethoxyethane (DME, 10 ml) and 2 M aqueous Na2CO3 solution (10 ml)
3. 3
   温度The reaction mixture is heated for 20 h to 80° C.
4. 4
   workup.ADDITIONdiluted with water and ethyl acetate
5. 5
   干燥The organic layer is dried (MgSO4)
6. 6
   过滤filtered
7. 7
   其他the solvents are evaporated
8. 8
   其他The residue is chromatographed with ethyl acetate/hexane (1:1)

实验过程

A mixture of 4-bromo-1-tert-butoxycarbonyl-2-(3,4,5-trimethoxyphenyl)-pyrrole (2.0 g, 5.0 mmol, Example 76b), Pd(PPh3)4 (290 mg, 0.25 mmol) and pyridine-3-boronic acid (614 mg, 5.0 mmol) are evacuated for 10 min and set under argon atmosphere, followed by addition of degassed dimethoxyethane (DME, 10 ml) and 2 M aqueous Na2CO3 solution (10 ml). The reaction mixture is heated for 20 h to 80° C., cooled to room temperature and diluted with water and ethyl acetate. The organic layer is dried (MgSO4), filtered and the solvents are evaporated. The residue is chromatographed with ethyl acetate/hexane (1:1) to yield first 1-tert-butoxycarbonyl-4-(3-pyridyl)-2-(3,4,5-trimethoxy-phenyl)-pyrrole (280 mg, 12%) as a yellowish amorphous solid and then the title compound (700 mg, 45%) as a yellowish solid, 1H-NMR (300 MHz, DMSO-d6): 11.52 (br.s, 1H); 7.88 (br. s, 1H); 8.33 (br.d; J=6.0, 1H); 8.0-7.95 (m, 1H); 7.48 (br.s, 1H); 7.35-7.3 (m, 1H); 7.07 (br.s, 1H); 7.02 (s, 2H); 3.85 (s, 2MeO); 3.67 (s, MeO).

来源