Trimethylene urea

Methyluracyl, the reaction product of acetoacetic ester and urea (water and alcohol being eliminated), can be easily reduced in sulphuric-acid solution (Tafel and Weinschenk2). Methyl-trimethylene urea is formed, also a considerable quantity of 1.3-diaminobutane ... 

Dimethyl carbonate (DMC) is a colorless liquid with a pleasant odor. It is soluble in most organic solvents but insoluble in water. The classical synthesis of DMC is the reaction of methanol with phosgene. Because phosgene is toxic, a non-phosgene-route may be preferred. The new route reacts methanol with urea over a tin catalyst. However, the yield is low. Using electron donor solvents such as trimethylene glycol dimethyl ether and continually distilling off the product increases the yield. ... 

Tetraaza-crown macrocycles, table, 378 Tetraaza-crown macrocycles (two trimethylene bridges), table, 383 Tetraaza-crown macrocycles (urea or thiourea), table, 384... 

An objection to the above proposals for the formation of network structures by the interaction of urea and formaldehyde is that they involve the participation of imido hydrogen atoms, which are known to be very unreactive towards methylol groups. In order to avoid this criticism, it has been suggested [4] that acidification of methylolureas yields methylene-imines which trimerize to give substituted trimethylene triamine compounds which then polymerize to a network structure by interaction of methylol and amine groups ... 

In earlier studies conducted by Hocker et al., the copolymerization of trimethylene carbonate and caprolactam was shown to give a poly(ester-urethane). In a similar way, tetramethylene urea can be copolymerized, using dimethyltrimeth-ylene carbonate and dibutylmagnesium as an initiator, to yield polyurethane chains [61, 62]. 

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