反应详情

Ethyl cyanoacetate (4.52 g) was added to a stirred solution of 2-propoxybenzamidine in ethanol (prepared from sodium, 1.84 g., in ethanol, 100 ml, and 2-propoxybenzamidine methanesulphonate, 11.61 g). The reaction mixture was stirred at ambient temperature for 18 hours and then evaporated under reduced pressure to leave a residue which was dissolved in water. The aqueous solution was extracted with diethyl ether (2×25 ml) and the combined ether extracts were washed with water. The combined aqueous phase was treated with glacial acetic acid to pH 5 to precipitate a crude product. Further crude product was obtained by extracting the ether extracts with 1 normal sodium hydroxide (2×30 ml) and acidifying the combined alkaline extracts with glacial acetic acid to pH 5. The combined crude product was recrystallised from isopropanol to yield the title compound, 2.34 g, m.p. 183.5°-184.5° C.

1. customevaporated under reduced pressure
2. customto leave a residue which
3. extractionThe aqueous solution was extracted with diethyl ether (2×25 ml)
4. washthe combined ether extracts were washed with water
5. additionThe combined aqueous phase was treated with glacial acetic acid to pH 5
6. customto precipitate a crude product
7. customFurther crude product was obtained
8. extractionby extracting the ether
9. customwas recrystallised from isopropanol