反応 #676787

反応方程式

42

6-Methylindole

norbornene

K2CO3

methyl 4-bromobutyrate

→

product 48

収率 23.2%

Methyl 4-(6-methyl-1H-indol-2-yl)butanoate

収率 23.2%

溶媒

ether

DMA

water

反応条件

後処理

1. 1
   その他The reaction mixture was evacuated
2. 2
   workup.ADDITIONback filled with argon three times
3. 3
   その他The reaction mixture was placed in a preheated oil bath at 70° C.
4. 4
   ろ過filtered
5. 5
   濃縮The filtrate was concentrated in vacuo at 60° C.
6. 6
   その他to remove ether
7. 7
   その他The residue was purified by flash column chromatography
8. 8
   洗浄eluting with a linear gradient

実験手順

A round bottom flask was charged with 42 (1.76 g, 13.4 mmol), norbornene (2.53 g, 26.9 mmol), K2CO3 (3.71 g, 26.9 mmol), and PdCl2(CH3CN)2 (0.35 g, 1.34 mmol). A solution of water in DMA (0.5 M, 10 mL) was then added. The reaction mixture was evacuated, back filled with argon three times, and then added with methyl 4-bromobutyrate (4.7 mL, 26.0 mmol). The reaction mixture was placed in a preheated oil bath at 70° C., and the mixture was stirred vigorously for 16 h under N2. The reaction was cooled to rt, diluted with ether, and filtered. The filtrate was concentrated in vacuo at 60° C. to remove ether and most of DMA. The residue was purified by flash column chromatography eluting with a linear gradient ranging from 0 to 40% EtOAc-hexanes to provide 0.72 g (23%) of product 48 as an off-white solid. 1H NMR (300 MHz, CDCl3) δ 1.98-2.07 (m, 2H), 2.40 (t, J=7 Hz, 2H), 2.43 (s, 3H), 2.80 (t, J=7 Hz, 1H), 3.66 (s, 3H), 6.18-6.19 (m, 1H), 6.91 (d, J=8 Hz, 1H), 7.09 (s, 1H), 7.40 (d, J=8 Hz, 1H), 7.90 (brs, 1H). LC-MS (CI): m/z 232.1 [(M+H)+ C14H17NO2 requires 231.13].

出典