1,4,8,11-Tetramethyl-1,4,8,11-tetraazacyclotetradecane41203-22-931 % similar N-Methylpiperidine626-67-531 % similar Arecoline63-75-231 % similar 1-Ethyl-2,3-piperazinedione59702-31-731 % similar 4-Methyl-1-piperazinecarbonyl chloride39539-66-730 % similar