反应详情

温度

0 °C

To a stirred suspension of 3.0 g. (0.0125 mole) of 6-amino-2,2-dimethyl-3-(5-tetrazolyl)penam in 15 ml of water is added 1.74 g (0.0125 mole) of bromoacetic acid dissolved in 5 ml of water. The pH of the mixture is adjusted to 610 using 20% sodium hydroxide solution. The resulting clear solution is cooled to 0° C., and then 2.4 g. (0.0125 mole) of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is added. The solution is stirred at 0° C. for a further 2.5 hr, during which time the pH is maintained between 6 and 7 by the addition of 6N hydrochloric acid. At this point, the pH is adjusted to 7.0 and the reaction mixture is extracted with ethyl acetate. The extract is discarded. The pH of the reaction mixture is then lowered to 2.0 (6N hydrochloric acid), and the product is extracted into ethyl acetate. The ethyl acetate is washed with water, dried, and evaporated to give 3.2 g (72% yield) of 6-(2-bromoacetamido)-2,2-dimethyl-3-(5-tetrazolyl)penam as a white foam. The infrared spectrum (KBr disc) of the product shows absorption bands at 1795 cm-1 (βlactam), 1670 cm-1 (amide I) and 1530 cm-1 (amide II). The NMR spectrum (CDCl3) shows absorption bands at 10.6-9.6 ppm (broad singlet, tetrazole hydrogen), 8.8 ppm (doublet, amide hydrogen), 5.8-5.4 ppm (multiplet, C-5 and C-6 hydrogens), 5.35 ppm (singlet, C-3 hydrogen), 4.0 ppm (singlet, methylene hydrogen), 1.90 ppm (singlet, C-2 methyl hydrogens) and 1.15 ppm (singlet, C-2 methyl hydrogens).

1. additionTo a stirred suspension of 3.0 g
2. extractionthe reaction mixture is extracted with ethyl acetate
3. extractionthe product is extracted into ethyl acetate
4. washThe ethyl acetate is washed with water
5. customdried
6. customevaporated