Preparation of Trichloroethylidene Urea

Chloral has also been shown to react with urea to give to(l-hydroxy-2,2,2-trichloroethyl) urea [34], 

This compound is useful for flame retarding polyurethanes and particularly polyurethane foam. 

Chloral can also be reacted with urea to give 1-hydroxy-2,2,2-trichloro-ethyl urea [34, 35] and with other ureas (linear and cyclic) as well as sulfamides to give 1-hydroxy-2,2,2-trichloroethyl derivatives as described in references 34, 35. Other references to ureas containing the 2,2,2-trichloroethyl groups or flame retardants for polyurethanes should also be consulted [35,36, 37]. 

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