The invention relates to processes and intermediates for preparing compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein R, R.sup.1, R.sup.2, and R.sup.3 are as defined herein. The above compounds of formula (I) are selective inhibitors of phosphodiesterase type IV and the production of tumor necrosis factor, and therefore may be used in the treatment of various inflammatory disorders such as asthma, joint inflammation, and other conditions or diseases. ##STR1##
该发明涉及制备式(I)化合物及其药学上可接受的盐的过程和中间体,其中R、R.sup.1、R.sup.2和R.sup.3如本文所定义。式(I)的上述化合物是
磷酸二酯酶IV的选择性
抑制剂和肿瘤坏死因子的产生,因此可用于治疗各种炎症性疾病,如哮喘、关节炎和其他情况或疾病。