Synthesis, Characterization, Structural, Benzotriazole, Benzothiadiazole and Benzoxadiazole

1. Synthesis, Characterization, Structural,
Benzotriazole, Benzothiadiazole and Benzoxadiazole
By
Wael AL-HARBI

2. C6H5N3
Chemical formula
99°C
Melting point
colourless crystals
Appearance
8.2
pKa
Information
Reaction
Synthesis
Applications
Information
 Benzotriazole is an extremely weak base.
 The fused benzene ring imparts additional stabilization to the
conjugate base
 Benzotriazole forms complexes with numerous metals, acting
frequently as a bridging ligand
 It is a stronger NH-acid than indazole, benzimidazole or 1,2,3-triazole.
Reference:[1]
indazole 1,2,3-triazole
benzimidazole
BTA

3. C6H5N3
Chemical formula
99°C
Melting point
colourless crystals
Appearance
8.2
pKa
Information
Reaction
Synthesis
Applications
Reaction
 Alkylation of benzotriazoles
 GRAEBE-ULLMANN reaction
Reference:[1]
BTA

4. C6H5N3
Chemical formula
99°C
Melting point
colourless crystals
Appearance
8.2
pKa
Information
Reaction
Synthesis
Applications
Synthesis
 The standard synthesis of benzotriazoles is the cyclocondensation of
o-phenylenediamines with sodium nitrite in acetic acid[1]:
N H 2
N H 2
R
H O N O
N H 2
N
H
R
N
O
N
H
N
N
O H
H
R
N
H
N
N
R
BTA

5. C6H5N3
Chemical formula
99°C
Melting point
colourless crystals
Appearance
8.2
pKa
Information
Reaction
Synthesis
Applications
Synthesis
Comparison of Conventional and Microwave-assisted Synthesis of
Benzotriazole Derivatives[2].
BTA

6. C6H5N3
Chemical formula
99°C
Melting point
colourless crystals
Appearance
8.2
pKa
Information
Reaction
Synthesis
Applications
Applications
Medical Industrial
Reference
Use
Structure
Name (IUPAC)
[1]
Antiemetic
6-Methoxy-3H-
benzotriazole-5-carboxylic
acid (1-allyl-pyrrolidin-2-
ylmethyl)-amide
N
N
H
N
O
NH
O
N
BTA

7. C6H5N3
Chemical formula
99°C
Melting point
colourless crystals
Appearance
8.2
pKa
Information
Reaction
Synthesis
Applications
Applications
Medical Industrial
Reference
Use
Structure
Name (IUPAC)
[1]
-prevention of sunburn
-photo stabilizers for
plastics, rubber and
chemical fibres
2-(2-hydroxy-5-
methylphenyl)
benzotriazole N
N
N
H
O
BTA

8. C6H4N2S
Chemical formula
42-44°C
Melting point
Form: crystalline
Colour: beige
Appearance
---------
pKa
Information
Reaction
Synthesis
Applications
Information
The 2,1,3-benzothiadiazole is an aromatic heterocycle with a planar
molecular structure[3].
The 2,1,3-benzothiadiazole (BTD) ring have re-have received much attention
in recent years, especially in the last decade, because of their potential use
in[3] :
This heterocyclic system has a strong electron-withdrawing capacity, and
compounds bearing this ring are possible candidates for
electron carriers[4].
Depending on the type of substituents and conjugation length, the 2,1,3-
benzothiadiazole based materials emit a variety of different colors including:
green red blue[4].
BTDs are one of the most important classes of conjugated systems because
of their relatively high reduction potential and electron affinity [4]
Antibacterial
Herbicides
Fungicides
Gene regulation
indazole
Fluorescent materials
BTD

9. C6H4N2S
Chemical formula
42-44°C
Melting point
Form: crystalline
Colour: beige
Appearance
---------
pKa
Information
Reaction
Synthesis
Applications
Reaction
BTD
Reference:[4]

10. C6H4N2S
Chemical formula
42-44°C
Melting point
Form: crystalline
Colour: beige
Appearance
---------
pKa
Information
Reaction
Synthesis
Applications
Reaction
BTD
Reference:[4]

11. C6H4N2S
Chemical formula
42-44°C
Melting point
Form: crystalline
Colour: beige
Appearance
---------
pKa
Information
Reaction
Synthesis
Applications
Synthesis
BTD
Reference:[4]

12. C6H4N2S
Chemical formula
42-44°C
Melting point
Form: crystalline
Colour: beige
Appearance
---------
pKa
Information
Reaction
Synthesis
Applications
Synthesis
BTD
N H 2
N H 2
S
O
O
C l
C l H
N
N H 2
S
O
O
C l
N
H
S
H
N O
O
C H 2C l2
N
S
N O H
O H
H
H
N
S
N
N
S
N

13. C6H4N2S
Chemical formula
42-44°C
Melting point
Form: crystalline
Colour: beige
Appearance
---------
pKa
Information
Reaction
Synthesis
Applications
Applications
BTD
Organic solar cells
OLED Technology
Biological
Compounds 168a,b could also be used to
selectively stain nuclear DNA in human
stem cells.

14. C6H4N2S
Chemical formula
42-44°C
Melting point
Form: crystalline
Colour: beige
Appearance
---------
pKa
Information
Reaction
Synthesis
Applications
Applications
BTD
Organic solar cells
OLED Technology
Biological
The liquid crystal transition temperatures
of homologues 150a–c decrease as the
chain length increases
Kelly and co-workers used the BTD unit in
the synthesis of new liquid crystal
molecules with the possibility of using
light-emitting liquid crystals for use in
OLEDs, especially with polarized emission

15. C6H4N2S
Chemical formula
42-44°C
Melting point
Form: crystalline
Colour: beige
Appearance
---------
pKa
Information
Reaction
Synthesis
Applications
Applications
BTD
Organic solar cells
OLED Technology
Biological

16. Chemical formula
°C
Melting point
Appearance
pKa
Information
Reaction
Synthesis
Applications
Information
The 2,1,3-benzoxadiazole heterocycle more specifically known as
benzofurazan is the oxygen containing analogue of 2,1,3 benzothiadiazole.
It also possesses a planar and conjugated bicyclic molecular structure and
its derivatives with extended conjugation are highly fluorescent.
Due to the presence of oxygen in the heterocycle, the benzofurazan is more
electronegative (more electron deficient) compared to 2,1,3-
benzothiadiazole.
Reference:[3]

17. Chemical formula
°C
Melting point
Appearance
pKa
Information
Reaction
Synthesis
Applications
Reaction
Reference:[3]

18. Chemical formula
°C
Melting point
Appearance
pKa
Information
Reaction
Synthesis
Applications
Synthesis
Reference:[3]

19. Chemical formula
°C
Melting point
Appearance
pKa
Information
Reaction
Synthesis
Applications
Application
use of 4-nitro-2,1,3-benzoxadiazole
derivatives of general formula (I) as
dye in colorants for keratin fibers
such as, for example, wool, silk, furs
or hair and particularly human.