1. HOOC COOH CH COOH NO 2. 3 CH C(CH3) N〈C-NH 5.(CH3)3C2COOH 6O2N/C-O NO2 COOH NO 8 COOH 21 January 202121 January 2021 4 HO O C C O O H C H 3 C H 3 C ( C H 3 ) 3 N O 2 C l CH 3 N O 2 C O O H C l O 2N C NH N O2 O ( C H 3 ) 3 C C O OH O 2 N C N O 2 O O N O 2 C O O H C 2 H5 C O OH 1. 2. 3. 4. 5. 6. 7. 8