反応 #45768

反応方程式

Ethyl 3-bromopyruvate

4-cyano-7-fluoro-5-methyl-6-phenyl-1,3-benzoxazole-2-carbothioamide

sodium hydrogencarbonate

p-toluenesulfonic acid monohydrate

→

compound

収率 91.3%

Ethyl 2-(4-cyano-7-fluoro-5-methyl-6-phenyl-1,3-benzoxazol-2-yl)-1,3-thiazole-4-carboxylate

収率 91.3%

溶媒

toluene

water

反応条件

後処理

1. 1
   温度by heating
2. 2
   温度After cooling to room temperature
3. 3
   温度by heating
4. 4
   温度under reflux in an oil bath at 125° C. for 15 hours
5. 5
   温度After cooling to room temperature
6. 6
   抽出followed by extraction with ethyl acetate (50 ml×2)
7. 7
   洗浄The organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution (50 ml) and saturated brine (50 ml)
8. 8
   乾燥dried over anhydrous sodium sulfate
9. 9
   濃縮After concentration
10. 10
    その他the resulting residue was purified by silica gel column chromatography (eluent, chloroform:ethyl acetate=100:1→25:1)

実験手順

Ethyl 3-bromopyruvate (72.2 μl, 0.518 mmol) was added to a toluene (10 ml) solution of 4-cyano-7-fluoro-5-methyl-6-phenyl-1,3-benzoxazole-2-carbothioamide (I-196-1) (124 mg, 0.398 mmol), followed by heating under reflux in an oil bath at 125° C. for 2 hours. After cooling to room temperature, p-toluenesulfonic acid monohydrate (15.2 mg, 0.080 mmol) was added to the reaction liquid, followed by heating under reflux in an oil bath at 125° C. for 15 hours. After cooling to room temperature, an aqueous saturated sodium hydrogencarbonate solution (50 ml) and water (50 ml) were added, followed by extraction with ethyl acetate (50 ml×2). The organic layer was washed with an aqueous saturated sodium hydrogencarbonate solution (50 ml) and saturated brine (50 ml), and dried over anhydrous sodium sulfate. After concentration, the resulting residue was purified by silica gel column chromatography (eluent, chloroform:ethyl acetate=100:1→25:1) to obtain the entitled compound (148 mg, 91.2%) as a pale yellow solid.

出典