Anti-allergy novel 1-oxo-1H-pyrimido[6,1-b]benzthiazole derivatives of the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each independently is hydrogen, halogen, hydroxy, nitro, trifluoromethyl, or lower alkyl, alkoxy or alkylthio, or R.sub.2 and R.sub.3 together are alkylenedioxy, and X is hydroxy, alkoxy or tetrazolyl-5-amino, or salts thereof, as well as their production by saponification of ##STR2## or tautomers thereof, followed by acidification.
抗过敏新型1-氧代-1H-
嘧啶并[6,1-b]
苯并噻唑衍
生物的
化学式为##STR1##其中R.sub.1、R.sub.2、R.sub.3和R.sub.4分别独立地为氢、卤素、羟基、硝基、三
氟甲基、或较低的烷基、烷氧基或烷
硫基,或者R.sub.2和R.sub.3一起为烷二氧基,而X为羟基、烷氧基或五唑-5-
氨基,或它们的盐。它们的生产方法是通过皂化##STR2##或其互变异构体,然后酸化。