1,4,7,10-tetrazacyclododecane

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 55 g of cyclen base (320 mmol) are dissolved in 550 ml of CH3CN, to which 119.8 g of brominated derivative (2-bromo-5-(1,3-dioxo-1,3-dihydroisoindol-2-yl)pentanoic acid benzyl ester, 288 mmol) dissolved in 550 ml of CH3CN are added dropwise. The medium is stirred at ambient temperature overnight. The precipitate is filtered off and washed thoroughly with acetonitrile. 138 g of product are obtained in the form of a white powder (corrected yield 81.3%). are added dropwise The precipitate is filtered off washed thoroughly with acetonitrile

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In 50 ml of chloroform was added 3.5 g (20.3 mmole) of 1,4,7,10-tetraazacyclododecane and 1.7 g (7.87 mmole) p-nitrobenzyl bromide and the mixture stirred under nitrogen for 24 hours at 25° C. The chloroform slurry of hydrobromide salt was then applied to a 1 in.×17 in. column of flash silica gel (Solvent System 3). There was obtained 2.13 g (6.93 mmole) of the title product as a pale yellow solid of analytical purity in 88 percent yield (Rf =0.58, Solvent System 3), MP=128°-129° C., and further characterized by: