4-Morpholino-2-(oxiran-2-ylmethyl)-1,2,5-thiadiazol-3(2H)-one is an intermediate for the synthesis of 2-(3-(tert-Butylamino)-2-hydroxypropyl)-4-morpholino-1,2,5-thiadiazol-3(2H)-one (B692940), which is a impurity of Timolol (T443710), an antihypertensive; antiarrhythmic (class II); antianginal; antiglaucoma agent.