p. 2225 - 2239
(2007/10/03)1-(benzyloxycarbonyl)-4-(tert-butoxycarbonyl)-2-piperazinecarboxylic acid
1-[(benzyloxy)carbonyl]-4-(tert-butoxycarbonyl)-2-methylpiperazine-2-carboxylic acid
1-benzyl-4-tert-butyl-2-cyano-2-methylpiperazine-1,4-dicarboxylate
1-benzyl 4-tert-butyl 2-[amino(hydroxyimino)methyl]-2-methylpiperazine-1,4-dicarboxylate
dimethyl acetylenedicarboxylate
1-benzyl 4-tert-butyl 2-[5-(benzoyloxy)-4-hydroxy-6-(methoxycarbonyl)pyrimidin-2-yl]-2-methylpiperazine-1,4-dicarboxylate
tert-butyl 3-(4-{[(4-fluorobenzyl)amino]carbonyl}-5,6-dihydroxypyrimidin-2-yl)-3,4-dimethylpiperazine-1-carboxylate
methyl 5-(benzoyloxy)-2-[4-(tert-butoxycarbonyl)-2-methylpiperazin-2-yl]-6-hydroxypyrimidine-4-carboxylate
2-(1,2-dimethylpiperazin-2-yl)-N-(4-fluorobenzyl)-5,6-dihydroxypyrimidine-4-carboxamide