Hydrochloric Acid → E 7820

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a suspension of 5.0 g (29 mmol) of the 7-amino-3-cyano-4-methyl-1H-indole obtained in Example 2A and 6.48 g (32 mmol) of 3-cyanobenzenesulfonyl chloride [CAS No. 56542-67-7] in 150 mL of methyl acetate, were added 75 mL of water and 2.83 mL (35 mmol) of pyridine, followed by stirring for 2 hours and 40 minutes. After adding 0.73 mL (9 mmol) of concentrated hydrochloric acid to the reaction mixture, liquid-liquid separation was performed and the organic layer was washed with a mixture of 75 mL of water and 17.5 mL of ethanol. Activated carbon was added to the organic layer and the mixture was stirred at 45-50° C. for 30 minutes, and then filtered and concentrated. To thus obtained crude crystals were added 96 mL of 2-butanol and 24 mL of water for dissolution at 75° C., and the solution was cooled to 7° C. at approximately 10° C./hr and stirred overnight. The precipitated crystals were collected by filtration and washed twice with 10 mL of 2-butanol to give 8.17 g (wet weight) of crystals of the title compound. The crystals were dried under reduced pressure at 70° C. for 2 hours to give 7.54 g of crystals of the title compound.

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