4-(N-Methylaminomethyl)-1-oxo-2,3,4,9-tetrahydrothiopyrano(2,3-b)indole oxalate 73424-88-1 Thiopyrano(2,3-b)indole-4-methanamine, 2,3,4,9-tetrahydro-N-methyl-, 1-oxide, ethanedioate (1:1)