| 摘要 |
PURPOSE:To obtain economically the titled compound of high quality useful as a dehydration condensing agent in synthesizing peptides, nucleic acid, etc., oxidation reaction assistant, etc., by treating dicyclohexylurea wit phosphorus oxychloride, and treating the resultant product without contact with water. CONSTITUTION:Dicyclohexylurea is reacted with an almost equimolar amount of phosphorus oxychloride in the presence of a pyridine base in large excess at 70-110 deg.C for 1-5hr. The resultant reaction product solution is then heated to <=75 deg.C, allowed to stand, and separated into two liquid layers. The upper layer is collected and distilled to give the aimed substance. Phosphoric acid, condensed phosphoric acid derivatives and hydrogen chloride formed as a by-product from the phosphorus oxychloride and hydrochloride of the pyridine base formed therefrom are present in the lower layer part, which is preferably neutralized with an alkali solution and extracted with a solvent to recover the pyridine base.
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