Tetraazacyclotetradecane nickel ll Perchlorate

The linear tetramine 1,5,8,12-tetraazadodecane required as starting material is prepared by the following procedure  

Nickel(II) perchlorate hexahydrate, 54.7 g (0.15 mole), is dissolved in 400 ml of water in a 2-1. beaker. With adequate stirring, 26 g (0.15 mole) of 1,5,-8,12-tetraazadodecane is added. The resulting red-brown solution is cooled to ca. 5° in an ice bath, and 30 ml of 30% (an equivalent amount of 40%may be used) glyoxal is added with stirring. The beaker is removed from the ice 

Cyclam is often desired as a ligand for other metal ions. The free base may be obtained in good yields by the following procedure without isolating the nickel complex. 

Transfer the solution obtained in Sec. A after reduction with sodium tetrahy-droborate (but before addition of perchloric acid) to a 1-1. single-necked flask with 29 g (0.6 mole) of sodium cyanide. Fit the flask with a condenser and reflux the solution for 2 hr. Cool the solution to room temperature, add 15 g of sodium hydroxide, and evaporate on a rotary evaporator until a semisolid remains. Chloroform, 100 ml, is added to the flask, and the mixture is transferred to a large frit. The liquid is drawn off, and the solid is washed twice with 100-ml portions of chloroform. The aqueous layer is then separated from the filtrate and washed five to seven times with 50-ml portions of chloroform. All the chloroform extracts are dried over sodium sulfate and then evaporated to dryness. The yellowish solid is recrystallized from 800 ml of chlorobenzene to yield white needles which are collected by suction and washed with 50 ml of ethyl ether. The product is then air-dried. A second crop obtained by evaporating the filtrate is treated similarly. Yield 19 g or 63%. Anal. Calcd. for CioH24N4 C, 59.99 H, 12.09 N, 28.01. Found C, 60.1 H, 11.8 N, 28.2. Alternatively, the free base may be recovered from the isolated nickel complex by the above procedure. 

Cyclam is obtained as a white fibrous solid after recrystallization from chlorobenzene and melts at 185-186°. The free base is very soluble in ethanol and chloroform but only slightly soluble in water. The infrared spectrum of the base contains strong N—H stretching absorptions at 3280 and 3200 cm i (Nujol mull). p/sTo values (at 20°) for the prolonated base are 10.76, 10.18, 3.54, and 2.67.9 

---