(3,4-Dihydroxybenzylidene)malononitrile (3,4-Dihydroxyphenyl)methylene propanedinitrile 118409-57-7 AG 18 Propanedinitrile, ((3,4-dihydroxyphenyl)methylene)- RG 50810 RG-50810 Tyrphostin 23 Tyrphostin A23 Tyrphostin AG18 Tyrphostin RG50810