8.00653

Selenium dioxide

(sublimed) for synthesis

• Synonym(s): Selenium dioxide, Selenious anhydride, Selenium(IV) oxide
• Empirical Formula (Hill Notation): O₂Se
• CAS Number: 7446-08-4
• Molecular Weight: 110.96
• UNSPSC Code: 12352303
• EC Index Number: 231-194-7
• NACRES: NA.22

Properties

• vapor pressure: <1 Pa ( 20 °C)
• Quality Level: 200
• form: crystals
• potency: 68.1 mg/kg LD₅₀, oral (Rat)
• reaction suitability: reagent type: oxidant
• pH: 2 (20 °C, 10 g/L in H₂O)
• mp: 340 °C
• solubility: 1353 g/L
• density: 3.95 g/cm³ at 20 °C
• storage temp.: 2-30°C
• InChI: 1S/O2Se/c1-3-2
• InChI key: JPJALAQPGMAKDF-UHFFFAOYSA-N

Description

Application

Selenium dioxide (SeO₂) is mainly used to oxidize the activated carbon-bearing positions (α-methylene carbon atoms), particularly at allylic or propargylic sites. The more substituted end of the double bond undergoes oxidation.
It can also be used as an oxidizing reagent to synthesize:

• Amides by oxidative amidation of aldehydes with amines.
• Tropone from cycloheptatriene in the presence of potassium dihydrogen phosphate.
• Acetyltetrahydrobenzofurans by oxidation of conjugated dienones.
• 9-hydroxy-undec-10-ynoate from methyl undec-10-ynoate.

Analysis Note

Assay (iodometric): ≥ 98.0 %

Safety Information

• pictograms: GHS06,GHS08,GHS09
• signalword: Danger
• hcodes: H301 + H331 - H373 - H410
• pcodes: P260 - P264 - P273 - P301 + P310 - P304 + P340 + P311 - P314
• Hazard Classifications: Acute Tox. 3 Inhalation - Acute Tox. 3 Oral - Aquatic Acute 1 - Aquatic Chronic 1 - STOT RE 2
• Storage Class: 6.1D - Non-combustible, acute toxic Cat.3 / toxic hazardous materials or hazardous materials causing chronic effects
• wgk_germany: WGK 2
• flash_point_f: Not applicable
• flash_point_c: Not applicable