反応 #62614

反応方程式

4-[(trimethylsilyl)oxy]-2H-1-benzopyran

ether

isopropyl ether

→

orange-red solid

収率 86.0%

4H-Furo[3,2-c][1]benzopyran-2,3-dione

収率 86.0%

反応条件

後処理

1. 1
   ろ過The precipitate is collected by filtration
2. 2
   洗浄washed with isopropyl ether

実験手順

To a stirred solution of 4-[(trimethylsilyl)oxy]-2H-1-benzopyran (L. H. Hellberg, and A. Zuarez, Tetrahedron Letters, 40, 3553 (1974)) (205.8 g, 0.917 mole) in anhydrous ether (600 ml) oxalyl chloride (58.2 g, 0.458 mole) is added dropwise over a period of 40 minutes at room temperature under nitrogen. The suspension is stirred at room temperature for 18 hours and then diluted with isopropyl ether (~300 ml). The precipitate is collected by filtration and washed with isopropyl ether to give 80.2 g (86%) of orange-red solid, mp 146°-8° C. Recrystallization from tetrahydrofuranisopropyl ether gives an analytical sample, mp 146°-148° C.

出典