1-butyl-3-[(6-methylpyridin-2-yl)methylideneamino]thiourea 1-butyl-3-[(6-methyl-2-pyridyl)methyleneamino]thiourea 6-Methyl-2-pyridinecarbaldehyde N-butylthiosemicarbazone AIDS-161144 AIDS161144 NSC673826 NCI60_026138