4-Amino-2-methylthiopyrimidine , with CAS number of 2183-66-6, can be called 4-pyrimidinamine, 2-(methylthio)- ; 2-(Methylsulfanyl)pyrimidin-4-amine ; Pyrimidine, 4-amino-2- (methylthio)- ; 4-Pyrimidinamine, 2- (methylthio)- .