p. 693 - 696
(2007/10/02)piperazine-1,3-dicarboxylic acid 1-tert-butyl ester
2-hydroxymethylpiperazine
1-(benzyloxycarbonyl)-4-(tert-butoxycarbonyl)-2-piperazinecarboxylic acid
4-(benzyloxy-carbonyl)-2-piperazinecarboxylic acid
piperazine-1,3-dicarboxylic acid 1-(4-nitrobenzyl)ester