| This paper aims at green synthetic chemistry, with the emphasis on study of green synthesis, mechanism and crystal structures of UF resin and 3, 3'-(alkanediyldiimino)dibut-2-enoates etc.The mechanism on preparation of UF resin is study in this paper, based on which a new method for preparing urea-formaldehyde resin by adding urea in four portions and formaldehyde in two portions is followed. Especially, most of the mount of urea and formaldehyde used in this method is the result of calculation according to this synthetic route. The urea-formaldehyde binder produced by this method is of high adhesive strength, low free formaldehyde content and low formaldehyde emission, meeting the standards of El and GB18580-2001.Diethyl 3, 3'-(ethane-l, 2-diyldiimino)dibut-2-enoate has been investigated extensively. It was normally prepared by condensation of ethyl acetoacetate with ethylenediamine in an anhydrous organic solvent, the presence of water usually being regarded as disadvantageous. Up to the year 2000, although Stefani and his co-workers reported the reaction of p-ketoester or 1, 3-diketone and ethylenediamine in water, the two reported structures are obviously contrary to our experimental results and even to its reported 1HNMR spectral data, still less the troublesome separation and purification. On the other hand, other dibut-2-enoates are less well-known so far. Offered in this paper is a method for green synthesis of several 3, 3'-(alkanediyldiimino)dbut-2-enoates. The novel N, N'-disubstituted aliphatic diamines are of interest as possible precursors of some heterocycles.In addition, molecular and crystal structures of diethyl 3, 3'-(ethane-1, 2-diyldiimino)dibut-2-enoate (I), 3-methyl-3-pyrazolin-5-one (II) and dimethyl 3, 3'-(propane-1, 2-diyldiimino)dibut-enoate (III) are offered in this paper. By X-ray analysis, we found polymorphism of 3-methyl-3-pyrazolin-5-one, Z, Z configurations of (I) and (III), studied some other interesting structural features of (I), (II) and (III).
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