To synthesize and characterized 2,3 diphenyl quninoxaline from orthophenelene diamnine (opd)

1. Experiment 6
To synthesize and characterized 2,3-
diphenylquinoxaline from orthophenelene
diamine (OPD).
Presented By….
Prof. Sonali R. Pawar
Medicinal Chemistry I
B. Pharmacy IV semester

2. Title: Synthesis of 2,3-Diphenyl quinoxaline from O-phenylene diamine (OPD).
Aim: To synthesize and characterized 2,3-Diphenyl quinoxaline from O-phenylene
diamine (OPD).
Chemicals
1. Filter Paper
1. Red & blue litmus paper
1. O-phenylene diamine 1.1 gm
2. Benzil 2.1 gm
2. Rectified Spirit 8 ml

3. Principle:
It is a pinacol rearrangement reaction: When O-phenylene diamine
react with benzyl will give 2,3-Diphenyl quinoxaline, they can form by
condensing O- diamine with 1,2-ketone the parent substance of the group
quinoxaline glycoxal is condensed with 1,2-diaminobenzene quinoxaline
and its analouges may also form by reduction of amino acid. Substituted
1,2-diphenyl quinoxaline form by condensation by benzyl and O-
phenylene diamine.

4. Procedure:
1) To a warm solution of 2.1 gm (0.01 mol) of benzyl in 8 ml of rectified spirit.
2) Add a solution of 1.1 gm (0.01 mol) of O-phenylene diamine in 8 ml of rectified
spirit.
3) Warm in a water bath for 30 min.
4) Add water until a slight cloud in perrist.
5) Allow to cool, filter and recrystallizes from aqueous ethanol to give 1.43 gm
(51%) of 2,3-Diphenyl quinoxaline. (Melting poing: 125-126 °C)
Used as anti-viral, anti-bacterial, anti-inflammatory, anti-protozoal, anti-cancer
(colon cancer therapies), antidepressant, anti-HIV agent and as kinase inhibitor
etc.

5. CALCULATIONS :-
Molecular weight of 2,3-diphenyl quinoxaline = 282.3gm/M
Molecular weight of OPD= 108.14gm/M
Weight taken of OPD =1.1gm/M
Practical yield = 2.83gm
X(theoretical yield )=molecular weight 2,3-diphenyl quinoxaline x weight of OPD taken
molecular weight of OPD
=282.3g/M x 1.1g/108.14g/M = 2.86gm
Percentage yield = practical yield /theoretical yieldx100%
Percentage yield =2.83/2.86x100%
Percentage yield = 98.95%

6. Calculation:
TLC:
Structure:
Formula: C10H14N2
Theorotical Yield: 2.86gm
Practical Yield: 2.83gm
% Yield: 98.95%
Melting/Boiling
Point:
1250c – 1260c
Rf Value: 0.53

7. SRP:Cholinergic Neurotransmitter
7