4-Nitrobenzyl 2-(3-benzyl-7-oxo-4-thia-2,6-diazabicyclo[3.2.0]hept-2-en-6-yl)-3-methylbut-3-enoate 25g

4-Nitrobenzyl 2-(3-benzyl-7-oxo-4-thia-2,6-diazabicyclo[3.2.0]hept-2-en-6-yl)-3-methylbut-3-enoate 25g