Through the reaction of 7-ADCA and Dane Salt, one step crystallization gives Cefalexin with the total yield 89.4% .

• 7-氨基-3-去乙酰氧基头孢烷酸(7-ADCA)和苯甘氨酸邓钠盐反应；只需要一步结晶即可得头孢氨苄；总收率89.；4%25。