反応 #1361813

反応方程式

Triphenylphosphine

carbon tetrabromide

5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-1,2-benzisothiazole-3-carboxaldehyde

→

title product

収率 83.6%

3-[3-(2,2-Dibromovinyl)-1,2-benzisothiazol-5-yl]-1-methyl-6-(trifluoromethyl)-2,4(1H,3H)-pyrimidinedione

収率 83.6%

溶媒

methylene chloride

methylene chloride

反応条件

後処理

1. 1
   濃縮concentrated in vacuo
2. 2
   その他The resultant residue is purified by flash column chromatography

実験手順

Triphenylphosphine (0.354 g, 0.00138 mol) is added to a solution of carbon tetrabromide (0.223 g, 0.000676 mol) in methylene chloride. The resultant mixture is stirred at room temperature for 10 minutes and treated dropwise with a solution of 5-[3,6-dihydro-3-methyl-2,6-dioxo-4-(trifluoromethyl)-1(2H)-pyrimidinyl]-1,2-benzisothiazole-3-carboxaldehyde (0.200 g, 0.000563 mol) in methylene chloride. The resultant mixture is stirred 20 minutes and concentrated in vacuo. The resultant residue is purified by flash column chromatography using silica gel and 10:1 methylene chloride/ethyl acetate to give the title product as a white solid (0.240 g, 83.6%, mp 260-262° C.) which is identified by NMR and IR spectral analyses.

出典