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ChemicalBook CAS DataBase List Dicyclohexylcarbodiimide
538-75-0

Dicyclohexylcarbodiimide synthesis

14synthesis methods
A stirred mixture of N,N′-dicyclohexylurea (19.7 g), phosphorus pentoxide (100 g), sand (175 g), and pyridine (700 mL) was refluxed for 2.25 h. Stirring was no longer possible after about 30 min. The mixture was filtered and the residue was extracted with pyridine (100 mL). Pyridine was removed from the combined solutions on a flash evaporator, and the residual oil was extracted with boiling petroleum ether (bp 60–80 C°) (2 × 100 mL), and then with diethyl ether (100 mL). The combined extracts were washed with iced water (3×80 mL), dried over calcium chloride, and filtered. The solvents were removed from the filtrate under reduced pressure to give 17.4 g of an oil, which on distillation yielded 13.7 g (76%) of a clear liquid; bp 143 C° (3.5 mmHg), which solidified in the receiver; mp 34–35 C°.
Another method for producing DCC from dicyclohexylurea is a two-step process using phosphoryl chloride in dichloromethane at 40 C° for 4 h under non-basic conditions followed by removal of acidic components with aq. sodium hydroxide. This method, which gives an 89% yield of DCC, has been presented in a patent application.
DCC.jpg
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Yield:538-75-0 99.5%

Reaction Conditions:

with bis(trichloromethyl) carbonate in 1-methyl-pyrrolidin-2-one at 30 - 40; for 6 h;Autoclave;

Steps:

3 Example 1

1000 ml of NMP and 100 g of DCU were added to the autoclave at 30 ° C, stirred well, 200 g of BTC was added, and thenAdding the composite catalyst (the dosage ratio of DCU and composite catalyst is 1: 0.0001), raising the temperature to 40 DEG C,Reaction 6h, after the completion of the reaction, add triethylamine to adjust the pH to 7.5, hot filter, atmospheric distillation of the solvent, and then vacuum distillationDistillate, collecting 155 ± 1 ° C distillate, in the oven vacuum drying to obtain a white crystalline solid DCC.

References:

CN105503656,2016,A Location in patent:Paragraph 0027; 0028

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