ChemicalBook Product Catalog Organic Chemistry Heterocyclic Compounds 5-Bromobenzo[c][1,2,5]oxadiazole

5-Bromobenzo[c][1,2,5]oxadiazole

Product Name5-Bromobenzo[c][1,2,5]oxadiazole
CAS51376-06-8
MFC6H3BrN2O
MW199
EINECS
MOL File51376-06-8.mol

Chemical Properties

Melting point	72 °C
Boiling point	255.8±32.0 °C(Predicted)
Density	1.826±0.06 g/cm3(Predicted)
storage temp.	Room temperature.
pka	-1.63±0.36(Predicted)
form	Solid
Appearance	Off-white to yellow Solid
InChI	InChI=1S/C6H3BrN2O/c7-4-1-2-5-6(3-4)9-10-8-5/h1-3H
InChIKey	ZWDFFESFCIACQC-UHFFFAOYSA-N
SMILES	N1=C2C=CC(Br)=CC2=NO1
CAS DataBase Reference	51376-06-8

Safety Information

Hazard Codes	Xi,Xn
Risk Statements	22
WGK Germany	WGK 3
Hazard Note	Irritant
HS Code	2934999090
Storage Class	11 - Combustible Solids
Hazard Classifications	Acute Tox. 4 Oral

Usage And Synthesis

Uses

5-Bromobenzo[c][1,2,5]oxadiazole, also known as 5-Bromo-2,1,3-benzoxadiazole, is a heterocyclic compound. It can be used as a pharmaceutical intermediate in drug synthesis. It is a derivative of benzo[c][1,2,5]oxadiazole which is a strong electron‐withdrawing unit compared to benzo[c][1,2,5]thiadiazole (BT). Hence BO is usually introduced as an acceptor to construct narrow band-gap donor-acceptor (D-A) materials[1]. BO is incorporated into the naphthalenediimide (NDI) based polymer backbone to improve the performance of polymer semiconductor.

Preparation

Triphenylphosphine (1.1 mmol) was dissolved in dry toluene (3 mL) and stirred at 110°C under argon atmosphere; then 6-bromobenzo[c][1,2,5]oxadiazole 1-oxide (1 mmol) in toluene (0.5 mL) was added dropwise over 1 hour and the resulting mixture was stirred for 3 hours. After completion, the solvent was evaporated in vacuo, and the crude was purified through flash column chromatography (cyclohexane - diethyl ether 98:2) to afford 5-Bromobenzo[c][1,2,5]oxadiazole which is a pale pink solid.
5-BROMO-2,1,3-BENZOXADIAZOLE

Synthesis

41153-83-7

51376-06-8

General procedure for the synthesis of 5-bromo-2,1,3-benzoxazole from 5-bromobenzo[2,1,3]oxadiazole 3-oxide: triphenylphosphine (1.1 mmol) was dissolved in anhydrous toluene (3 mL) and stirred at 110 °C under argon protection. Subsequently, a solution of 6-bromobenzo[c][1,2,5]oxadiazole 1-oxide (1 mmol) in toluene (0.5 mL) was slowly added dropwise over a period of 1 h. Stirring of the reaction mixture was continued for 3 h after completion of the dropwise addition. After completion of the reaction, the solvent was removed by distillation under reduced pressure and the crude product was purified by fast column chromatography (eluent: cyclohexane-ether, 98:2) to afford the target compound 5-bromo-2,1,3-benzoxazole as a light pink solid. Yield: 60%. Thin layer chromatography (TLC) conditions (cyclohexane-ether, 98:2): rf = 0.5. melting point: 74 °C. 1H-NMR (300 MHz, DMSO-d6) δ: 8.49 (s, 1H, H4), 8.04 (d, J = 9.4 Hz, 1H, H7), 7.69 (dd, J = 9.4, 1.6 Hz, 1H, H6).

References

[1] Song X, et al. Fusing Benzo[c][1,2,5]oxadiazole Unit with Thiophene for Constructing Wide-bandgap High-performance IDT-based Polymer Solar Cell Donor Material. Macromolecular Rapid Communications, 2018; 39: 1700782.

5-Bromobenzo[c][1,2,5]oxadiazole

Chemical Properties

Safety Information

Usage And Synthesis

Preparation Products And Raw materials

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