The present invention relates to a method for the preparation of compounds having the following formula (I):
in which:
R1, R2, R3, and R4 represent, independently from each other, in particular H or an alkyl group having from 1 to 20 carbon atoms,
said method comprising the reaction of a compound of formula (II)
R1 and R2 being as defined above,
with a compound having the following formula (III):
R3 and R4 being as defined above,
in the presence of a catalytic amount of an acid.
本发明涉及一种制备具有以下
化学式(I)的化合物的方法:其中:R1、R2、R3和R4分别代表特定的H或具有1至20个碳原子的烷基基团,所述方法包括将具有
化学式(II)的化合物与具有以下
化学式(III)的化合物在酸的催化下反应,其中R1和R2如上定义,R3和R4如上定义。