This invention relates to substituted 2-aminothiochromones of the general structure I: ##STR1## wherein R.sub.1 and R.sub.2 may be hydrogen; lower alkyl or lower alkoxy of 1 to 6 carbon atoms; or halogen such as chloro or bromo; and X may be cyano or carboxamido. The compounds are prepared using a thiosalicylic acid or a substituted thiosalicylic acid as starting material. The compounds of this invention are active in the prevention of allergic and asthmatic reactions in mammals.