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US 2023/0095750 A1Published application
Flow chemistry synthesis of isocyanates
AssigneeThe Regents of the University of California
InventorsMichael D. Burkart, Thien An Phung Hai
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Abstract
The disclosure provides, inter alia, safe and environmentally-friendly methods, such as flow chemistry, to synthesize isocyanates, such as methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and tetramethylxylene diisocyanate.
Claims56
A continuous flow process for producing an isocyanate, the process comprising:
- (i) mixing an acyl hydrazide with an aqueous solution comprising nitrous acid in flow to form a first solution comprising an acyl azide and water;
- (ii) mixing an organic solvent with the first solution in flow to produce a second solution comprising the acyl azide compound, the organic solvent, and water;
- (iii) removing water from the second solution in flow to produce a third solution comprising the azide compound and the organic solvent;
- and
- (iv) heating the third solution comprising the azide compound in flow to produce the isocyanate.
2 more elements
A process for producing at least one gram of an isocyanate, the process comprising:
- (i) mixing an acyl hydrazide with an aqueous solution comprising nitrous acid to form a first solution comprising an acyl azide and water;
- (ii) mixing an organic solvent with the first solution to produce a second solution comprising the azide compound, the organic solvent, and water;
- (iii) removing water from the second solution to produce a third solution comprising the azide compound and the organic solvent;
- and
- (iv) heating the third solution comprising the azide compound to produce at least one gram of the isocyanate.
2 more elements
Dependencies are inferred from the claim text.