Page 71 - Pharmaceutical Organic Chemmistry-3 (Theoritical book) 24-25

Clinical Pharmacy PharmD - 2024/2025 Level 2 Pharmaceutical Organic Chemistry-3 (PC 305)
Phthalazine

It is prepared by condensation of phthaldialdehyde with hydrazine.

H
C O H N
+ H 2 N
C O 2 N -2H O N
2
H phthalazine
phthalaldehyde
o-Dicarbonylbenzenes or o-acylbenzoic acids give substituted phthalazines.

Halogens at the 4-position can be easily substituted by nucleophiles.

Cl NHR
Cl Cl
N RNH 2 N

N N

Quinoxalines (benzopyrazine)

Obtained by condensing o-phenylenediamines with 1,2-dicarbonyl compounds:

NH 2 O C R N R

NH 2 O C R N R

2,3-dialkylquinoxaline

V- Six-Membered Rings with
More Than Two Heteroatoms (self-learning)