Jozef Hodyl PhD Thesis - Theses - Flinders University

For the purpose of spectral characterisation crude 53 was purified by refrigerationin ether for 7 days after which time a white solid precipitated. The white solid wasfiltered under nitrogen and washed with copious quantities of ether to give 53 as afine extremely hygroscopic white powder in 92% yield. 13 C NMR (CDCl 3 ): δ 166.10(1 C, C=O); 165.25 (1 C, C=O); 163.76 (1 C, C=O); 163.76 (1 C, C=O); 162.97 (1C, Bn); 157.54 (1 C, Bn); 135.87 (2 C, Bn); 129.15 - 128.71 (2 C, Bn); 67.86 - 67.67(1 C, Bn-CH 2 ); 52.56-43.29 (8 C, cyclen -CH 2 ).1-(benzyloxycarbonyl)-1,4,7,10-tetraazadodecane•3HCl•1.5H 2 O, 5555A solution of 53 (504 mg, 1.38 mmol), dissolved in HCl, (1M, 35 cm 3 , 35 mmol),was stirred a 50 o C for 5 h after which the solvent was removed completely in vacuoat 60 o C to yield an off-white solid. The crude product was suspended in ethanol (20cm 3 ), refluxed for 1 h, cooled to room temperature, filtered and dried in air to yield55: 1 st crop 64 mg, 12%. Excess ether was added to the filtrate to assess thecloudiness of the solution and the white precipitate filtered and washed with ether (1x 5 cm 3 ) and dried in air to yield 55: 2 nd crop 450 mg 84%. Both crops exhibitedequal purity and were combined for an overall yield of, 514 mg, 96%. (Found C,43.22; H, 7.45; N, 12.50. C 16 H 29 Cl 3 N 4 O 2 •1.5H 2 O requires C, 43.40; H, 7.28; N,12.65%). 1 H NMR (D 2 O/1,4-dioxane): δ 7.45 (5 H, br s, Bn-H); 5.21 (2 H, br s, Bn-CH 2 ); 3.72 (4 H, br s, cyclenCH 2 ); 3.20 (12 H, br s, cyclenCH 2 ). 13 C NMR (D 2 O/1,4-134