Novel Cross-Linking Alkylating Agents, 1-(2-Chloroethyl)-3-methyl-3-acyltriazenes

Article abstract of DOI:10.1021/jo00242a022

The preparation and hydrolytic decomposition of a series of novel cross-linking alkylating agents, 1-(2-chloroethyl)-3-methyl-3-acyltriazenes, is described.The synthesis 3-carbethoxy-1-(2-chloroethyl)-3-methyltriazene, 3-acetyl-1-(2-chloroethyl)-3-methyltriazene, and 1-(2-chloroethyl)-3-methyl-3-(methylcarbamoyl)triazene has been accomplished through the use of a common intermediate, 1-<2-(tert-butyldimethylsiloxy)ethyl>-3-methyltriazene, bearing a key protecting group on the 2-ethyl position.Following acylation, the blocking group was removed with tetra-n-butylammoniu m fluoride and the resulting alcohol was converted to the desired chloro substituent by reaction with carbon tetrachloride and triphenylphosphine.Kinetic studies on the proteolytic decomposition at neutral pH of the (2-chloroethyl)triazenes, the corresponding (2-hydroxyethyl)triazenes, and the analogous 1,3-dimethyl-3-acyltriazenes revealed that the reactions proceed by N₂-N₃ heterolysis.The rates of the reactions are dependent on the stabilities of the incipient alkyldiazonium ions and on the ability of the 3-acyl substituens to stabilize the adjacent nagative charge.