反应详情

5 g (6.2 mmoles) of formamidine hydrochloride is added at 0° C. and in small quantities into a single-necked flask containing 30 ml of absolute ethanol and 90 ml of a solution of sodium ethylate at a concentration of 1.7 mol/l in ethanol. Stirring is maintained at ambient temperature for about twenty minutes, then 8.5 ml of dimethyl methoxymalonate is added dropwise. Stirring is maintained for 16 hours. The reaction mixture is then acidified with pure acetic acid to a pH between 4 and 5, then concentrated to dryness in the presence of cyclohexane. After impasting the crude product obtained is chromatographed on silicagel eluting with a mixture of methylene chloride-methanol (85-15)and 2% water-acetic acid (1-1). 9.5 g of the expected product is obtained containing a small quantity of sodium acetate salts.

1. stirringStirring
2. temperatureis maintained for 16 hours
3. concentrationconcentrated to dryness in the presence of cyclohexane
4. customobtained
5. customis chromatographed
6. washon silicagel eluting with a mixture of methylene chloride-methanol (85-15)and 2% water-acetic acid (1-1)