反応 #458917

反応方程式

6,7-dichloro-2,3-dihydro-benzofuran-2-carboxylic acid

furan-2-carbonyl-chloride

aluminum chloride

→

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

溶媒

methylene chloride

反応条件

後処理

1. 1
   workup.STIRRINGThe reaction solution is stirred 18 hours at 25° C.
2. 2
   温度refluxed for 1 hour
3. 3
   その他The solvent is removed
4. 4
   workup.ADDITIONthe residue added to ice water (200 ml.) and hydrochloric acid (20 ml.)
5. 5
   抽出The product is extracted into ether
6. 6
   洗浄washed with water
7. 7
   抽出extracted into aqueous sodium bicarbonate (200 ml.) from which the sodium salt of the product
8. 8
   その他precipitates
9. 9
   その他The sodium salt of the product is placed in a separatary funnel with dilute hydrochloric acid (100 ml.) and ether (100 ml.)
10. 10
    workup.STIRRINGshaken until the solid
11. 11
    workup.DISSOLUTIONdissolves
12. 12
    洗浄The ether solution is washed with water, brine
13. 13
    乾燥dried over magnesium sulfate
14. 14
    workup.DISTILLATIONthe ether distilled at reduced pressure
15. 15
    その他The 6,7-dichloro-2,3-dihydro-5-(2-furoyl)benzofuran-2-carboxylic acid melts at 166° C after crystallization from acetonitrile/n-butyl chloride

実験手順

To a well stirred mixture of 6,7-dichloro-2,3-dihydro-benzofuran-2-carboxylic acid (3.3 g.), furan-2-carbonyl-chloride (3.6 g.) and 200 ml. methylene chloride, protected from the atmosphere with a calcium chloride tube is added anhydrous aluminum chloride (3.7 g.) over a one-half hour period. The reaction solution is stirred 18 hours at 25° C. and then refluxed for 1 hour. The solvent is removed and the residue added to ice water (200 ml.) and hydrochloric acid (20 ml.). The product is extracted into ether, washed with water, then extracted into aqueous sodium bicarbonate (200 ml.) from which the sodium salt of the product precipitates. The sodium salt of the product is placed in a separatary 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-furoyl)benzofuran-2-carboxylic acid melts at 166° C after crystallization from acetonitrile/n-butyl chloride.

出典