Novel compounds of the formula ##STR1## wherein R is hydrogen, a straight or branched alkyl group having from 1 to 8 carbon atoms or benzyl; wherein each of R.sub.1 and R.sub.2 is hydrogen, an aralkyl group, a straight or branched hydrocarbon group having from 1 to 20 carbon atoms and may be saturated or unsaturated, an alkyl group of from 1 to 6 carbon atoms wherein the terminal carbon is substituted, the group --(CH.sub.2).sub.p)--Q wherein p is zero to three and Q is a 5- or 6-membered monocyclic or fused bicyclic heterocycle, phenyl or NR.sub.1 R.sub.2 taken together form a monocyclic heterocyclic ring, and R.sub.3 is phenyl, substituted phenyl, naphthyl, substituted naphthyl, --(CH.sub.2).sub.p --Q wherein p and Q are as defined above, an aralkyl group or a straight or branched hydrocarbon group having from 1 to 20 carbon atoms and being straight or branched.
式子为 ##STR1## 的新化合物,其中R为氢、1-8个碳原子的直链或支链烷基或苄基;R.sub.1和R.sub.2各自为氢、芳基烷基、1-20个碳原子的直链或支链烃基,可以饱和或不饱和,1-6个碳原子的烷基,其中末端碳原子被取代,--(CH.sub.2).sub.p)--Q中p为0-3,Q为5-或6-元杂环或融合的双环杂环、苯基或NR.sub.1 R.sub.2共同形成单环杂环;R.sub.3为苯基、取代苯基、
萘基、取代
萘基、--(CH.sub.2).sub.p--Q其中p和Q如上所定义、芳基烷基或1-20个碳原子的直链或支链烃基,可以是直链或支链。