Synthesis of biurea

Preparation of biurea

Preparation of biurea from hydrazine sulfate

Preparation of biurea from hydrazine sulfate and potassium cyanate.png

Preparation of biurea from hydrazine sulfate and potassium cyanate.png

65 grams of hydrazine sulfate (0.5 mol) are added to a mixture of 30 g of glacial acetic acid (0.5 mol) in 1000 ml of water. 89 grams of potassium cyanate (1.1 mol) are dissolved in 300 ml of water, the obtained solution is added to this solution portion-wise with constant stirring. Considerable gas evolution takes place, and the temperature rises to about 40° C. The acetic acid serves to adjust the final pH to approximately 4.8. After the mixture has been allowed to digest for 4 hours at room temperature with constant stirring, the biurea is filtered by suction and washed with 300 ml of water, followed by ethanol and ether. The dry product should weigh from 53 to 55 g (90 to 93% yield). The biurea is quite pure and need not be recrystallized.

Preparation of biurea from hydrazine hydrate

Preparation of biurea from hydrazine hydrate and potassium cyanate.png

Preparation of biurea from hydrazine hydrate and potassium cyanate.png

Hydrazine hy­drate may be substituted for hydrazine sulfate in the prep­aration of biurea. In this case, it is necessary to supply enough additional acetic acid to compensate for the absence of sulfuric acid. Thus, 29 g of 85% hydrazine hydrate (0.5 mol) and 90 g of glacial acetic acid (1.5 mol) are dis­solved in 500 ml of water. 89 grams of potassium cyanate (1.1 mols) in 300 ml of water are added to this solution. This must be done carefully and in 50-ml portions since vigorous gas evolution takes place. The final pH is about 5.4. After 4 hours of digestion, the biurea is recovered as described above. The yield and the purity of the product are the same as when hydrazine sulfate is used (90-93%).

Inorganic Syntheses, Vol. 4, 1953, 26-28.





InChI Key


Canonical SMILES


Depositor-Supplied Synonyms

Biurea, Ureidourea, 1,2-HYDRAZINEDICARBOXAMIDE, Bicarbamamide, Bicarbamimidic acid, 110-21-4, Hydrazocarbonamide, Urea, ureido-, Hydrazodicarbonamide, Hydrazodicarboxamide, Hydradicarbonamide, Pseudourea, 3-ureido-, N,N’-Dicarbamoylhydrazine, (carbamoylamino)urea, hydrazine-1,2-dicarboxamide, Semicarbazide, 1-carbamoyl-, Formimidic acid, 1-semicarbazido-, N,N’-Biscarbamoylhydrazine, Ureidoureacarboxamide, Hydrazine, 1,2-dicarbamoyl-, Formamide, 1,1′-hydrazobis-, 1,1-Hydrazoformamide, Semicarbazide, 1-(1-hydroxyformimidoyl)-, Hydrazinedicarboxylic acid diamide, NSC 1897, Hydrazinecarboximidic acid, 2-(aminocarbonyl)-, Hydrazine, 1,2-bis(aminocarbonyl)-, Bicarbamimidic acid (VAN), 1,1′-Hydrazobis(formamide), CCRIS 5976, HSDB 5014, EINECS 203-747-2, AI3-28537, Hydrazodiformamide, Biscarbamoylhydrazine, Carbamoylsemicarbazide, Hydrazinedicarboxamide, AC1Q5JJY, Hydrazine,2-dicarbamoyl-, UNII-POJ4UOY01H, Formamide,1′-hydrazobis-, DSSTox_CID_4628, POJ4UOY01H, 1-(aminocarbonylamino)urea, 1,1′-Hydrazinebisformamide, AC1L1Q4I, DSSTox_RID_77474, DSSTox_GSID_24628, SCHEMBL21785, KSC177M6R, CHEMBL3188383, CTK0H7668, Hydrazine,2-bis(aminocarbonyl)-, NSC1897, MolPort-003-909-729, ULUZGMIUTMRARO-UHFFFAOYSA-N, KST-1B8739, NSC-1897, Tox21_300989, AR-1B5992, LS-502, STL281876, ZINC04284404, AKOS005174048, MCULE-1306740070, NCGC00248246-01, NCGC00254891-01, AN-22591, CAS-110-21-4, CJ-11843, KB-48102, DB-040907, B0512, FT-0606465, R1547, ST50409446, A840149, I14-30123, 3B1-000396, 3B3-021744

Removed Synonyms

CID8039, 81-49-2, 77107-48-3

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