Abstract: A process for the preparation of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid and the salts thereof of formula (I) ##STR1## which comprises the following steps: a) carboxymethylation reaction of a suitable precursor in water, with a haloacetic acid,b) hydrolysis reaction in basic conditions by addition of the base added at the previous step.

Abstract: Procedures for preparing compounds of formula (I) ##STR1## in which n, p and q or independently 0 or 1, are prepared according to the reaction scheme: ##STR2##

Abstract: A process for the preparation of tetraazamacrocycles of general formula (I) ##STR1## wherein n, p and q can independently be 0 or 1, comprising the following steps:a): condensation of polyamines with a glyoxal derivative;b): condensation of the resulting compound with an alkylating agent;c): oxidation of the resulting compound with an oxidizing agent, to give a mixture of oxidated products which is submitted tod): hydrolysis in acid aqueous solution, to give the compound of formula (I).

Abstract: A process for the preparation of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid and the salts thereof of formula (I) ##STR1## which comprises the following steps: a) carboxymethylation reaction of a suitable precursor in water, with a haloacetic acid,b) hydrolysis reaction in basic conditions by addition of the base added at the previous step.

Abstract: A process for the preparation of complexes of macrocyclic chelants with paramagnetic metal trivalent ions of formula (XII) ##STR1## wherein R.sub.1, R.sub.2 and Me.sup.3+ are as described in the following, comprising: a) reaction of 1,4,7,10-tetraazacyclododecane with triethyl orthoformate to give 5H,9bH-2a,4a,7,9a-octahydrotetraazacycloocta[cd]pentalene; b) carboxymethylation reaction in water; c) hydrolysis reaction in basic conditions; d) alkylation according to known methods with an epoxide in water; e) complexation according to known methods carried out in water by addition of a paramagnetic metal salt; f) purification by diafiltration, final desalting of the aqueous solution on ion exchange resins and g) crystallization or recovery.

Abstract: A process for the preparation of complexes of macrocyclic chelants with paramagnetic metal trivalent ions of formula (XII) ##STR1## wherein R.sub.1, R.sub.2 and Me.sup.3+ are as described in the following, comprising: a) reaction of 1,4,7,10-tetraazacyclododecane with triethyl orthoformate to give 5H,9bH-2a,4a,7,9a-octahydrotetraazacycloocta[cd]pentalene; b) carboxymethylation reaction in water; c) hydrolysis reaction in basic conditions; d) alkylation according to known methods with an epoxide in water; e) complexation according to known methods carried out in water by addition of a paramagnetic metal salt; f) purification by diafiltration, final desalting of the aqueous solution on ion exchange resins and g) crystallization or recovery.

Abstract: A process for the preparation of tetraazamacro-cycles of general formula (I) ##STR1## wherein n, p and q can independently be 0 or 1, comprising the following steps:a): condensation of polyamines with a glyoxal derivative;b): condensation of the resulting compound with an alkylating agent;c): oxidation of the resulting compound with an oxidizing agent, to give a mixture of oxidated products which is submitted tod): hydrolysis in acid aqueous solution, to give the compound of formula (I).

Abstract: A process for the preparation of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid and the salts thereof of formula (I) ##STR1## which comprises the following steps: a) carboxymethylation reaction of a suitable precursor in water, with a haloacetic acid,b) hydrolysis reaction in basic conditions by addition of the base added at the previous step.

Abstract: A process for the preparation of complexes of macrocyclic chelants with paramagnetic metal trivalent ions of formula (XII) ##STR1## wherein R.sub.1, R.sub.2 and Me.sup.3+ are as described in the following, comprising: a) reaction of 1,4,7,10-tetraazacyclododecane with triethyl orthoformate to give 5H,9bH-2a,4a,7,9a-octahydrotetraazacycloocta?cd!pentalene; b) carboxymethylation reaction in water; c) hydrolysis reaction in basic conditions; d) alkylation according to known methods with an epoxide in water; e) complexation according to known methods carried out in water by addition of a paramagnetic metal salt; f) purification by diafiltration, final desalting of the aqueous solution on ion exchange resins and g) crystallization or recovery.

Abstract: A process for the preparation of tetraazamacrocycles of general formula (I) ##STR1## wherein n, p and q can independently be 0 or 1, comprising the following steps:a): condensation of polyamines with a glyoxal derivative;b): condensation of the resulting compound with an alkylating agent;c): oxidation of the resulting compound with an oxidizing agent, to give a mixture of oxidated products which is submitted tod): hydrolysis in acid aqueous solution, to give the compound of formula (I).