methyl 1,4,8,11-tetrazacyclotetradecane-6-carboxylate

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 5.00 g (16.2 mmol) of compound 3 prepared in the preceding stage in 50 ml of absolute methanol is brought to reflux. 30 ml of a 35% aqueous hydrochloric acid solution are added in small amounts. Reflux is maintained for 48 hours. The mixture is cooled to 0° C. and the precipitate formed is filtered off and then washed with ice-cold methanol. The filtrate is evaporated and then the residue is taken up in the minimum amount of methanol. The precipitate formed is filtered off and washed with ice-cold methanol. Compound 5·4HCl is isolated in the form of a white powder (4.55 g, Yield =76%). Overall yield starting from the tetraamine: 72%. to reflux Reflux is maintained for 48 hours the precipitate formed is filtered off washed with ice-cold methanol The filtrate is evaporated The precipitate formed is filtered off washed with ice-cold methanol is isolated in the form of a white powder (4.55 g, Yield =76%) Overall yield

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 5.00 g (16.2 mmol) of compound 3 prepared in the preceding stage in 50 ml of absolute methanol is brought to reflux. 30 ml of a 35% aqueous hydrochloric acid solution are added in small amounts. Reflux is maintained for 48 hours. The mixture is cooled to 0° C. and the precipitate formed is filtered off and then washed with ice-cold methanol. The filtrate is evaporated and then the residue is taken up in the minimum amount of methanol. The precipitate formed is filtered off and washed with ice-cold methanol. Compound 5·4HCl is isolated in the form of a white powder (4.55 g, Yield =76%). Overall yield starting from the tetraamine: 72%. to reflux Reflux is maintained for 48 hours the precipitate formed is filtered off washed with ice-cold methanol The filtrate is evaporated The precipitate formed is filtered off washed with ice-cold methanol is isolated in the form of a white powder (4.55 g, Yield =76%) Overall yield

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 5.00 g (16.2 mmol) of compound 3 prepared in the preceding stage in 50 ml of absolute methanol is brought to reflux. 30 ml of a 35% aqueous hydrochloric acid solution are added in small amounts. Reflux is maintained for 48 hours. The mixture is cooled to 0° C. and the precipitate formed is filtered off and then washed with ice-cold methanol. The filtrate is evaporated and then the residue is taken up in the minimum amount of methanol. The precipitate formed is filtered off and washed with ice-cold methanol. Compound 5·4HCl is isolated in the form of a white powder (4.55 g, Yield =76%). Overall yield starting from the tetraamine: 72%. to reflux Reflux is maintained for 48 hours the precipitate formed is filtered off washed with ice-cold methanol The filtrate is evaporated The precipitate formed is filtered off washed with ice-cold methanol is isolated in the form of a white powder (4.55 g, Yield =76%) Overall yield