A process for the preparation of Compound (I) comprising reacting Compound (II) with a base in an aprotic solvent, which is represented by the following scheme:
wherein R1 and R2 are each independently lower alkyl.
                            一种制备化合物(I)的方法,包括在无质子溶剂中用碱反应化合物(II),其
化学方程式如下所示:其中R1和R2各自独立表示低级烷基。