CAS 65481-32-7 3,9-Dimethylspiro[5.5]undecane Phosphonate Dioxide
Identified by CAS 65481-32-7, this is pure 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, a building block for organophosphorus ligands. HTS 2931.48.00.00 covers it as a non-halogenated organo-phosphorus derivative.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If classified as other organo-inorganic with additional non-P elements
Residual 'other' in 2931.90 catches compounds not specified earlier, per numerical order rule.
If nitrogen-function compounds with P incidental
Nitrogen functions in 2920 take precedence if primary over organo-inorganic.
If for rubber/plastic accelerators emphasizing end-use
Prepared rubber accelerators classify in Chapter 38 if not pure compounds.
Not sure which classification is right?
The Tariff Assistant works through the GRI rules on your specific product to reach the right HTS code — and can price the duty on it in the same conversation.
Import Tips & Compliance
• Reference CAS number on all shipping docs for rapid identification
• Ensure no impurities push it into mixtures excluded by Chapter notes
• Use UN-approved packaging for phosphorus compounds
Related Products under HTS 2931.48.00.00
3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide
This is a specific non-halogenated organo-phosphorus compound featuring a spirocyclic structure with two phosphonate groups, classified under HTS 2931.48.00.00 as an organo-inorganic compound where phosphorus is directly linked to carbon. It is used primarily as a synthetic intermediate in pharmaceutical and agrochemical production.
Antioxidant 552 (3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide)
Antioxidant 552 is the commercial grade of 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, a non-halogenated organo-phosphorus stabilizer for polymers. It falls under HTS 2931.48.00.00 due to its specific spiro phosphonate structure with P-C bonds, as defined in Chapter 29 heading 2931.
DOPO Derivative 3,9-Dimethylspiro Phosphonate
A DOPO-based derivative, this compound is precisely 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, used in flame-retardant synthesis for electronics. Classified in HTS 2931.48.00.00 as a non-halogenated organo-phosphorus compound per Chapter 29 definitions.
Spiro Phosphonate Monomer for Polymer Synthesis
This research-grade spiro phosphonate monomer, chemically 3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, is used in copolymer production. It qualifies under HTS 2931.48.00.00 for its organo-inorganic phosphorus structure excluding halogens.