for the following products
Cefpiramide acid side chain | D-alpha-(4-Hydroxy-6-methylnicotinamido)-4-hyroxylphenyl acetic acid | D-alpha-(6-Methyl-4-hydroxy-nicotinic acid amide)-P-hydroxyphenyl acetic and 2-(4-Hydroxy-6-methylnicotinamido)-2-(4-hydroxyphenyl)acetic acid