tert-Butyl 2'-(methylthio)-6'-oxo-5'-(((trifluoromethyl)sulfonyl)oxy)-6'H-spiro[cyclohexane-1,9'-pyrazino[1',2':1,5]pyrrolo[2,3-d]pyrimidine]-7'(8'H)-carboxylate, 97%, 50mg