23 3 mmol ethanol 60 ml water 13 ml and a stirrer bar then a cold 0 u00b0 c mixture of lioh 0 49 g 12 mmol p bromotoluic acid 1 00 g 4 65 mmol water 50 ml and ethanol 15 ml was added to the cyclen solution in one portion with stirring the reaction mixture was refluxed for 3 5 h allowed to cool to room temperature and concentrated to ca 30 ml using rotary evaporation the resulting solution was extracted with chcl 3 until no more cyclen remained in the chcl 3 washings ca 1000 ml the aqueous phase was treated drop wise with conc hcl ca 7 ml with stirring followed by ethanol 10 ml the resulting white precipitate was collected by filtration washed with ethanol and ether 50 ml and dried in air to give 1 see scheme 1 as a hygroscopic white powder 0 49 g 1 1 mmol 24 anal calcd for c 16 h 30 cl 4 n 4 o 2 c 42 40 h 6 89 n 12 36 found c 42 10 h 6 92 n 13 02 ir kbr pellet u03bd c u2550 o 1730 cm u2212 1 1 h nmr d 2 o u03b48 07 d 3 j 8 8 hz 2h c 6 h 4 u2014 7 52 d 3 j 8 4 hz 2h c 6 h 4 3 92 s 2h c 6 h 4 ch 2 3 25 2 89 m 19h of 8ch 2 3nh co cycmba cl 2 cl u2022 1 5h 2 o method.