Novel heterocyclic esters of benzopyranopyridines represented by the formula ##STR1## wherein R.sub.1 is hydrogen, lower alkyl, lower alkanoyl, cycloalkyl-lower alkyl, cycloalkyl-lower alkanoyl, lower alkenyl, lower alkynyl, halo-loweralkenyl, phenyl-lower alkyl, phenyl-lower alkenyl or phenyl-lower alkynyl; R.sub.2 is lower alkyl; R.sub.3 is an alkyl having one to twenty carbon atoms or a cycloalkyl-lower alkyl, Y is a straight or branched chain alkylene having one to eight carbon atoms, and R.sub.4 is a group of the formula ##STR2## a is an integer from 1 to 4, b is an integer from 1 to 4 and X is CH.sub.2, O, S or N--R.sub.5 with R.sub.5 being hydrogen or lower alkyl, with the limitation that when X is O, S or N--R.sub.5, a and b each must be 2 and R.sub.6 is hydrogen or a lower alkyl group bonded to a carbon in the ring; and the acid addition salts thereof.
                            这是一种新型杂环酯化合物,其
化学式为##STR1##其中,R.sub.1为氢、低碳基、低脂肪酰基、环烷基-低碳基、环烷基-低脂肪酰基、低烯基、低炔基、卤代低烯基、苯基-低碳基、苯基-低烯基或苯基-低炔基;R.sub.2为低碳基;R.sub.3为一种具有1到20个碳原子的烷基或环烷基-低碳基;Y为一种具有1到8个碳原子的直链或支链烷基;R.sub.4为##STR2##其中,a为1到4的整数,b为1到4的整数,X为CH.sub.2、O、S或N--R.sub.5,R.sub.5为氢或低碳基;需要注意的是,当X为O、S或N--R.sub.5时,a和b必须分别为2,且R.sub.6为与环中碳原子相连的氢或低碳基;此外,还包括其酸加成盐。