反応 #458916

反応方程式

6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid

thiophene-2-carbonyl chloride

aluminum chloride

→

(±)6,7-Dichloro-2,3-dihydro-5-(2-thenoyl)benzofuran-2-carboxylic acid

溶媒

hydrochloric acid

反応条件

後処理

1. 1
   その他protected from the atmosphere with a calcium chloride tube
2. 2
   温度The reaction mixture is heated at 80°-90° C. for 31/2 hours
3. 3
   抽出The product is extracted into ether
4. 4
   洗浄washed with water
5. 5
   抽出extracted into aqueous sodium bicarbonate (100 ml.) from which the sodium salt of the product
6. 6
   その他precipitates
7. 7
   その他The sodium salt of the product is placed in a separatory funnel with dilute hydrochloric acid (100 ml.) and ether (100 ml.)
8. 8
   workup.STIRRINGshaken until the solid
9. 9
   workup.DISSOLUTIONdissolves
10. 10
    洗浄The ether solution is washed with water, brine
11. 11
    乾燥dried over magnesium sulfate
12. 12
    workup.DISTILLATIONthe ether distilled at reduced pressure
13. 13
    その他The (±)6,7-dichloro-2,3-dihydro-5-(2-thenoyl)benzofuran-2-carboxylic acid melts at 187° C. after crystallization from butyl chloride

実験手順

To a well stirred mixture of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid (2.6 g.) and thiophene-2-carbonyl chloride (4 ml.) protected from the atmosphere with a calcium chloride tube is added anhydrous aluminum chloride (6.0 g.) over a 1-hour period. The reaction mixture is heated at 80°-90° C. for 31/2 hours then poured into ice water (100 ml.) and hydrochloric acid (10 ml.). The product is extracted into ether, washed with water, then extracted into aqueous sodium bicarbonate (100 ml.) from which the sodium salt of the product precipitates. The sodium salt of the product is placed in a separatory funnel with dilute hydrochloric acid (100 ml.) and ether (100 ml.) and shaken until the solid dissolves. The ether solution is washed with water, brine, dried over magnesium sulfate and the ether distilled at reduced pressure. The (±)6,7-dichloro-2,3-dihydro-5-(2-thenoyl)benzofuran-2-carboxylic acid melts at 187° C. after crystallization from butyl chloride.

出典