1,4,7-Trimethyl-1,4,7-triazacyclononane

50-00-0

52667-89-7

96556-05-7

The general procedure for the synthesis of 1,4,7-trimethyl-1,4,7-triazacyclononane from formaldehyde and 1,4,7-tri-tosyl-1,4,7-triazacyclononane is as follows: 10.37 g of 1,4,7-tri-toluenesulfonyl-1,4,7-triazacyclononane (Ts3TACN) was added to a 30 mL round-bottomed flask, followed by the addition of 10 mL of of concentrated sulfuric acid mixed with 2 mL of distilled water. The reaction vessel was placed in an oil bath, heated to 140 °C, and the solid was completely dissolved by stirring to form a black solution. The reaction was kept at 140°C with continued stirring for 6 hours. Upon completion of the reaction, the resulting solution was slowly poured into a 500 mL two-necked flask which was pre-filled with 32 g of 50% (w/w) aqueous sodium hydroxide solution and 13 g of distilled water while being cooled in an ice bath. Subsequently, 23 mL of 37% formaldehyde aqueous solution and 23 mL of 88% formic acid were added to the reaction system and the mixture was heated to 90 °C, at which time carbon dioxide gas was observed to be generated. After the release of gas ceased, the reaction mixture was cooled to 0 °C and 50 g of 50% (w/w) aqueous sodium hydroxide solution was added. Next, 200 mL of hexane was added and after stirring for 2 min, the organic phase was separated using a separatory funnel. The aqueous phase was further extracted with hexane and all hexane phases were combined and dried with anhydrous sodium sulfate. Finally, the organic phase was concentrated under reduced pressure to afford the target product 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3TACN) in 25% yield.