反応 #339968

反応方程式

5-methylsalicylaldehyde

K2CO3

dimethylbromomalo-nate

→

title compound 583

収率 42.1%

Methyl-5-methyl-benzofuran-2-carboxylate

収率 42.1%

溶媒

toluene

反応条件

後処理

1. 1
   温度The suspension was heated
2. 2
   温度to reflux with a Dean-Stark trap for 20 h
3. 3
   濃縮concentrated in vacuo
4. 4
   ろ過filtered
5. 5
   洗浄The filtrate was washed with H2O, 1N NaOH and brine
6. 6
   乾燥The organic layer was dried over magnesium sulfate
7. 7
   ろ過filtered
8. 8
   濃縮concentrated
9. 9
   その他The crude residue was purified by column chromatography (10% ethyl acetate/hexane)

実験手順

A stirring suspension of 5-methylsalicylaldehyde (1.0 mg, 7.5 mmol), K2CO3 (1.55 g, 11.0 mmol), and Bu4NBr (322 mg, 1 mmol) in toluene (30 ml) was treated with dimethylbromomalo-nate (1.06 ml, 8.0 mmol). The suspension was heated to reflux with a Dean-Stark trap for 20 h. The brown suspension was cooled to 25° C. and concentrated in vacuo. The residue was taken in DCM and filtered. The filtrate was washed with H2O, 1N NaOH and brine. The organic layer was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by column chromatography (10% ethyl acetate/hexane) to afford the title compound 583 (600 mg, 42% yield). LRMS: 190.2 (Calc.); 191.1 (found).

出典