CA2098712A1 - Chelating agents - Google Patents
Chelating agentsInfo
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- CA2098712A1 CA2098712A1 CA002098712A CA2098712A CA2098712A1 CA 2098712 A1 CA2098712 A1 CA 2098712A1 CA 002098712 A CA002098712 A CA 002098712A CA 2098712 A CA2098712 A CA 2098712A CA 2098712 A1 CA2098712 A1 CA 2098712A1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/24—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with substituted hydrocarbon radicals attached to ring carbon atoms
- C07D213/36—Radicals substituted by singly-bound nitrogen atoms
- C07D213/40—Acylated substituent nitrogen atom
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- A61P39/00—General protective or antinoxious agents
- A61P39/02—Antidotes
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C237/00—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups
- C07C237/02—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups having the carbon atoms of the carboxamide groups bound to acyclic carbon atoms of the carbon skeleton
- C07C237/04—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups having the carbon atoms of the carboxamide groups bound to acyclic carbon atoms of the carbon skeleton the carbon skeleton being acyclic and saturated
- C07C237/10—Carboxylic acid amides, the carbon skeleton of the acid part being further substituted by amino groups having the carbon atoms of the carboxamide groups bound to acyclic carbon atoms of the carbon skeleton the carbon skeleton being acyclic and saturated having the nitrogen atom of at least one of the carboxamide groups bound to an acyclic carbon atom of a hydrocarbon radical substituted by nitrogen atoms not being part of nitro or nitroso groups
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D209/00—Heterocyclic compounds containing five-membered rings, condensed with other rings, with one nitrogen atom as the only ring hetero atom
- C07D209/02—Heterocyclic compounds containing five-membered rings, condensed with other rings, with one nitrogen atom as the only ring hetero atom condensed with one carbocyclic ring
- C07D209/04—Indoles; Hydrogenated indoles
- C07D209/10—Indoles; Hydrogenated indoles with substituted hydrocarbon radicals attached to carbon atoms of the hetero ring
- C07D209/18—Radicals substituted by carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals
- C07D209/20—Radicals substituted by carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals substituted additionally by nitrogen atoms, e.g. tryptophane
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D211/00—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings
- C07D211/04—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D211/06—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members
- C07D211/36—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D211/56—Nitrogen atoms
- C07D211/58—Nitrogen atoms attached in position 4
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/72—Nitrogen atoms
- C07D213/75—Amino or imino radicals, acylated by carboxylic or carbonic acids, or by sulfur or nitrogen analogues thereof, e.g. carbamates
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D295/00—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms
- C07D295/04—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms
- C07D295/12—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms substituted by singly or doubly bound nitrogen atoms
- C07D295/125—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms substituted by singly or doubly bound nitrogen atoms with the ring nitrogen atoms and the substituent nitrogen atoms attached to the same carbon chain, which is not interrupted by carbocyclic rings
- C07D295/13—Heterocyclic compounds containing polymethylene-imine rings with at least five ring members, 3-azabicyclo [3.2.2] nonane, piperazine, morpholine or thiomorpholine rings, having only hydrogen atoms directly attached to the ring carbon atoms with substituted hydrocarbon radicals attached to ring nitrogen atoms substituted by singly or doubly bound nitrogen atoms with the ring nitrogen atoms and the substituent nitrogen atoms attached to the same carbon chain, which is not interrupted by carbocyclic rings to an acyclic saturated chain
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2602/00—Systems containing two condensed rings
- C07C2602/02—Systems containing two condensed rings the rings having only two atoms in common
- C07C2602/04—One of the condensed rings being a six-membered aromatic ring
- C07C2602/08—One of the condensed rings being a six-membered aromatic ring the other ring being five-membered, e.g. indane
Abstract
There are provided chelating agents of formula (I) (wherein n is 0 or 1 and at least one R1 group comprises a group NR11R14 where one of R11 and R14 comprises a cyclic lipophilic group) and metal chelates and salts thereof. The chelates with paramagnetic or heavy metal ions are particularly suited for use as hepatobiliary contrast agents.
Description
2 ~ 9 ~ 71 ~ PCT/EP9~2~68 .
~i'`.` :
-- 1 ~ i CHELATING AGENTS
The present invention relates to chelat.in~ agents, more particularly aminopolycarboxylic acid chelants, and metal chelates thereof and the use of such chelating agents and chelates in diagnostic imaging, radiotherapy or heavy metal detoxification, and in particular as hepatobiliary contrast agents.
Medical uses of chelating agents are well established, for example as stabilizers for pharmaceutical preparations, as antidotes for poisonous heavy metal species and as agents for the administration, in chelate form, of metal ions for radiotherapy or diagnostic ima~ing, e.g. X-ray, magnetic resonance imaging (MRI), ultrasound or scintigraphy.
Aminopolycarboxylic acids and derivatives thereof (hereinafter referred to as APCAs) are well known as particularly effective chelants and are described in a wide range of publications, for example in US-A-2407645 (Bersworth), EP-A-71564 (Schering), EP-A-130934 (Schering), EP-A-165728 (Nycomed), US-A-4647447 (Schering), US-A-4826673 (Mallinckrodt), US-A-4639365 (Sherry), EP-A-26305s (Schering), EP-A-230893 (Bracco), EP-A-325762 (Bracco), WO-A-86/06605 (Lauffer), US-A-4746507 (Salutar), EP-A-290047 (Salutar), WO-A-90/01024 (Mallinckrodt), US-A-4687659 (Salutar) and EP-A-299795 (Nycomed) and in the documents cited in these patent publications.
Thus, for example, EP-A-71564 describes paramagnetic metal chelates, for which the chelating agent is nitrilotriacetic acid (NTA), N,N,N',N'-ethylenediaminetetraacetic acid (EDTA), N-hydroxyethyl-N,N',N'-ethylenediaminetriacetic acid (HEDTA), N,N,N',N",N"-diethylenetriaminepentaacetic acid (DTPA) and N-hydroxyethylimino-diacetic acid, as being suitable as contrast agents for MRI, contrast being .. .. : . , ~, . ........... . . ........... :~
:
WO~/11232 ~ ~ 9 ~ 7 12 PCT/E~Y~/0~46~
achieved by the effect of the magnetic field of the paramagnetic species (e.g. Gd(III)) with the chelatin~
agents serving to reduce the to~icity and to assist administration of the paramagnetic species.
Amongst the particular metal chelates disclosed by EP-A-71564 was -the dimeglumine salt of GdDTPA, the use of which as an MRI contrast agent has recently received much attention.
To improve stability, water solubility and selectivity, relative to the APCA chelating agents described in EP-A-71564, Schering in EP-A-130934 proposed the partial substitution for the N-attached carboxyalkyl groups of alkyl, alkoxyalkyl, alkoxycarbonylalkyl or alkylaminocarbonylalkyl groups, where any amide nitrogens may themselves carry polyhydroxy-alkyl ~roups.
For reduced toxicity, Salutar Inc, in for example US-A-4687659, has proposed the use as MRI contrast agents of chelates of paramagnetic metal ions and bisamides of DTPA, in particular DTPA-bismethylamide ~n the same patent, Salutar suggested that for imaging of the liver chelates of DTPA-bisthigher alkyl-amides) might be used.
In this field of hepatobiliary MRI contrast agents Nycomed, in EP-A-165728, have also proposed the use of paramagnetic chelates of certain anilide group-containing iminodiacetic acids and Lauffer in WO-A-86/0660S has suggested the use of paramagnetic chelates of various benzene ring containing chelants, e.g.
ethylene-bis-(2-hydroxyphenyl glycine) (EHPG), bist2-hydroxybenzyl)-ethylenediamine diacetic acid (HBED), benzo- and dibenzo-DTPA and triaza and tetraaza macrocycles which carry a fused benzene ring.
Still further APCA chelants for use in preparing MRI contrast agents have been proposed by Bracco in EP-A-230893 and EP-A-325762. These for the most par-t carry aryl or aralkyl substituents on the alkylene part of one - . ::, - ,. . :, , : .. ' :, ,.: . , . .: . - . . , WO92/11232 PCr/~ 6~
2 0 9 ~ ~J 1 ?
or more of the nitrogen-attached carboxyalkyl complex-forming moieties. Among the chelates covered is GdBOPTA, in which the chelant BOPTA has a DTPA structure with one N3 carboxymethyl replaced by a 2-benzyloxy-l-carboxy-ethyl group. GdBOPTA has been described by Vittadini et al in CMR '89, MRl9 as a liver~-specific ~RI
contrast agent.
Schering in EP-A-263059 have proposed a further range of DTPA and EDTA amide chelants for use in preparing MRI contrast agents. While commenting on the high lipophilicity of the DTPA-bisamides proposed by Salutar in WO-A-86/02841 (equivalent to US-A-4687659 discussed above), Schering have exemplified such compounds as GdDTPA-bispentylamide, GdDTPA-bisbutylamide and GdDTPA-phenylamide as well as chelates of further DTPA-alkylamides in which the alkyl moieties are substituted by hydrophilic groupings such as hydroxyl and alkoxy groups.
There is however a general and continuing need Eor APCA chelants which form metal chelates of reduced toxicity, improved stability, improved water solubility or improved biodistribution (e.g. enhanced tissue or organ specificity).
We now propose certain improved chela~ing agents, in particular amide derivatives of APCAs.
Viewed from one aspect therefore the invention provides chelants of formula I
HOOC CH2 ~ . ~ CH2COOH
NCH2CH2 [ NCH2CH2 ] nN ~ ( I ) R10CCH2 ~ CH2COR
(wherein n is 0 or l;
one group R1 is a group NR11R14 where R11 is a hydroxyl or alkoxy group or a group -L-Cy or -O-L-Cy, and R14 is a hydrogen atom, an alkyl group or a group -L-Cy, and the : . . ,. :: , :,. . , . :-W092/11232 PCT/E~ 2~
2~S7~2 other group R1 is a hydroxyl group or a group NR1lR14; L
is a bond or a straight-chain or branched saturated or unsaturated alkylene group optionally interrupted by a carbocyclic or heterocyclic saturated or unsa~urated group and optionally attached to the Cy group by a peptid~ or carbonyl link and optionally substituted ~y further Cy groups or by aminocarbonyl, acyl or acylamino groups; and Cy is a cyclic lipophilic group, eg a carbocyclic or heterocyclic saturated or unsaturated group itself optionally carrying one or more fused carbocyclic or heterocyclic saturated or unsaturated rings and optionally substituted by halogen atoms (eg iodine, chlorine or bromine), alkyl, al~ylamino, dialkylamino, carbamoyl, N-alkylcarbamoyl, acetamido, N-alkylacetamido and carbocyclic or heterocyclic saturated or unsaturated groups; with the provisos that in any NR11R14 group one of R11 and R14 group comprises a L-Cy group and that where n is 1 at least one R1 is other than phenylamine, benzylamine or methoxybenzylamine) and metal chelates and salts thereof.
Unless speci~ied otherwise, all alkyl or alkylene moieties in the compounds of the invention preferably contain up to ~0, particularly preferably up to 6, carbon atoms. The lipophilic Cy groups and the other cyclic rings in the compounds of formula I are particularly preferably mono or polycyclic groups containing 5 to 7 ring members in each ring, the rings if heterocyclic containing up to 3, preferably 1 or 2, non-adjacent ring heteroatoms selected from 0, N and S.
Preferred such rir.gs include benzene, pyridine, pyrimidine, pyrazine, 1,3-oxazine, 1,4-oxazine, 1,3-thiazine, 1,4-thiazine, pyrrole, imidazole, 1,3-oxazole, 1,3-thiazole, furan, thiophene, piperidine, piperazine, morpholine, perhydro-1,4-thiazine and pyrrolidine.
Thus particular examples of lipophilic Cy groups include groups of formula Ia to Ie , .: : . . :
; : ; :, . , ,., : :
.:. :: . .: :, :. , .: : , ~ :.
WO 92/11232 2 3 9 8 ~12 P~lER~ 2A68 ~;
R ~ R s ~:
R 3 ~ R 6 ~) y \~X "
R R7 ( I b) ( I c) , :
( la) /N
R 9 ( I d ) and other condensed a'cyclic rings (where R3 to R8 is each independently a bond or a hydrogen or halogen atom or an alkyl, alkylamino, .
dialkylamino, carbamoyl, N-alkylcarbamoyl, acetamido or N-alkylacetamido group or two adjacent groups from R3 to R8 together form a C25 alkylene or azaalkylene bridge, the point of attachment to L being a carbon of said bridge or one of said groups R3 to R8; X is nitrogen or CH and Y is CH or nitrogen; X' is CH2, NH, oxygen, sulphur or a bond; X" is nitrogen, oxygen or sulphur and Y" is CH or nitrogen; and R9 is a bond or hydrogen, alkyl or aralkyl, eg benzyl; such rings preferably not having ring heteroatoms at adjacent ring positions).
The linker moiety L is conveniently a branched or linear alkylene chain, eg such that LCy is of formula --(CHRt)k--(CO)a--(NR1)b-(CO)C--R10 where k is 0-10, especially 1 to 8, more especially 1 to ... ... . .. . . . . ..
WO9~tll232 PCT/E~
2~987 l2 ~
6; a, b and c are O or l, the sum of a and c being 0 or l; each R10 is a hydrogen atom, an alkyl group, an optionally esterified carboxyl group or a group Cy, at least one and preferably only one being a group Cy, and one or more CHR10 moieties may optionally be replaced by a 5-7 membered saturated homo or heterocyclic ring.
The carboxyl groups in the compounds of formula I
may, for example, be in the form of carboxylate salt groups, for example groups of formula -COOMt (where ~t is a monovalent cation or a fraction of a polyvalent cation, for example an ammonium or substituted ammonium ion or a metal ion, for example an alkali metal or alkaline earth metal ion). Particularly preferably, Mt is a cation deriving from an organic base, for example meglumine.
It is also particularly preferred that the number of the ion-forming carboxyl groups in the compounds of formula I be chosien to equal the valency of the me-tal species to be chelated by the compound of formula I.
Thus, for example, where Gd(III) i5 to be chelated, the chelating agent of formula I preferably contains three ion-forming -COOH or -COOM~ groups. In this way, the metal chelate will be formed as a neutral species, a form preferred since the osmotic pressures in concentrated solutions of such compounds are low and since their toxicities relative to their ionic analogues are significantly reduced.
Preferably the compounds of the invention contain two -L-Cy groups and particularly preferred compounds according to the invention include the chelants of formula II
A
HooccH2NCH2CH2 [NC~2CH2) n NCH2CH (II) R13NRlSCocH2 CH2COOH CH2coNR1sR13 (where n is 0 or l, R1s is hydrogen or methyl ., . : : : . :: :: , . . :: .:: :
WO~2/11232 2 0 9 ~ 7 1 2 PCTIEWI/0~68 and R13 is a group selected from benzyl, 2-phenyl-ethyl, 1-phenyl-ethyl, pyrid-4-yl, pyrid-3-yl, pyrid-2-yl, 3-morpholino-propyl, N-benzyl-piperidin-4-yl and inda~yl groups and iodinated such groups), and the metal chelates and salts thereof.
The chelant compounds of the invention may be prepared by amidation, eg analogously to EP-A-130934 (Schering~ and US-A-4687~59 (Salutar) of EDTA or DTPA or an activated or protected derivative thereof (eg an acid anhydride or bisanhydride) with an amine compound of formula III
HNR11'R14' (III) (where R11 and R14 are groups R11 and R14 as hereinbefore -defined or protected such groups), followed where necessary by deprotection.
As protecting groups, conventional protecting groups may be used, for example groups such as are described by T.W. Greene in "Protective Groups in Organic Synthesis", John Wiley & Sons, 1981.
Alternatively the compounds may be prepared in two or more stages, in the first reacting DTPA, EDTA or a derivative thereof to introduce one or two NR11 R14 groups (~here one of R11 and R14' is a group R11 or R1b and the other is a Cy-free analogues of R11 or R14) and in a second stage to introduce the Cy groups, eg by a peptide condensation reaction.
The amidation reactions are preferably performed in the liquid phase. Thus for example a solution of the amine in a solvent such as water, dipolar aprotic solvents, such as acetonitrile, N-methylpyrrolidone, N-methylmorpholine, dimethylformamide, dimethylacetamide, dimeth~vl sulfoxide, tetrahydrofuran and the like or mixtures thereof is prepared. The anhydride is added in portions or optionally dissolved in a dipolar aprotic anhydrous solvent such as acetonitrile, N-,, , .: ~ : . ;~, , . ~ . :
. .: :: :: . : , ~.:. :
:
WO92/11232 2 ~ 9 37 ~ 2 PCT/EP~ $ ~
methylpyrrolidone, N-methylmorpholine, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran and the like or mi~tures thereof. The reaction mixture is stirred under a nitrogen atmosphere for a period ranging between 0.5 hour and 3 days, preferably between l hour and 24 hoursO
The reaction temperatures generally range between about 0C and 100C, temperatures of about 20C to 80OC being preferred. For solvents with a low boiling point (l00C
or less) the reaction mixture can eventually be evaporated to dryness. For the solvents with higher boiling points, further solvents such as for example diethylether may be added and/or cooling may be used to precipitate the product.
Thus for example the bisamide chelants may be prepared by amidation as follows:
a) the amine of formula III is dissolved in a dry polar aprotic solvent, e.g. acetonitrile or chloroform, in a ratio of about l:l0 w:v amine:solvent. The bisanhydride of DTPA (or EDTA) (0.5 equivalents to the amine~ is added as dry powder in portions, with thorough stirring, and the reaction is allowed to proceed overnight. In the case of less reactive amines such as for example 2-aminopyridine, extensive refluxing may be necessary. In most cases the product precipitates from the reaction mixture and can be collected by filtration.
Otherwise the product can be precipitated by addition of diethyl ether and/or by cooling.
In the case of the bis-amides with non-heterocyclic side groups, the product may be puri~ied as follows: the precipitate from à) is dissolved in deionized water, and if necessary the pH is adjusted to 8-l0 using dilute NaOH. The pH is then adjus~ed to 3-3.5 with dilute HCl, and the precipitate is collected by filtration.
Chelants of formula I may be used as the basis for bifunctional chelants or for polychelant compounds, that ~. : , ... . ... .
', . . . ; . ~ .. , .. .,: :
WO92/11232 2 a ~ ~ 7 ~ /E~
' _ 9 _ :
is compounds containing several independent chelant groups, by substituting for a hydrogen atom or hydroxyl group a bond or linkage to a macromolecule or polymer~
e.g. a tissue specific biomolecule or a backhone polymer such as polylysine or polyethyleneimine which may carry several chelant groups and may itself be attached to a macromolecule to produce a bifunctional-polychelantO
Such macromelecular derivatives of the compounds of formula I and the salts and metal chelates t~ereof fo:~m a further aspect of the present invention. -The linkage of a compound of formula I to a macromolecule or backbone polymer may be effected by any of the conventional methods such as the carbodiimide method, the mixed anhydride procedure of Krejcarek et al. (see Biochemical and Biophysical Research Communications 77: 581 (1977)), the cyclic anhydride method of Hnatowich et al. (see Science 220: 613 (1983) and elsewhere), the backbone conjugation techniques oE
Meares et al. (see Anal. Biochem. 142: 68 (1984) and elsewhere) and Schering (see EP-A-331616 for example) and by the use of linker molecules as describéd for example by Nycomed in W0-A-89/06979.
Formation of salts and chelates of the chelants of the invention may again be performed in a conventional manner.
The chelating agents of the present invention are particularly suitable for use in detoxification or in the formation of me~al chelates, chelates which may be used for example in or as contrast agents for in vivo or in vitro magnetic resonance (MX), X-ray or ultrasound diagnostics (e.g~ MR imaging and MR spectroscopy), or scintigraphy or in or as therapeutic agents for radiotherapy, and such metal chelates form a particularly important embodiment of the present invention.
Salts or chelate comple~es of the compounds of the invention containing heavy metal ions are particularly : . . . : , ., - . . : . . ., , ~ , :
WO92/11232 PCT/EP~ 2~
2 ~ ~ r~ g 2 1~ 1 ) useful in diagnostic imaging or therapy. Especially preferred are salts or complexes with metals of atomic numbers 20-32, 42 44, 49 and 57 to 83, particularly Gd, Dy and Yb.
For use as an MR-diagnostics contrast agent, the chelated metal ion is particularly suitably a paramagnetic ion, the metal conveniently bein~ a transition metal or a lanthanide, preferably having an atomic number of 21-29, 42, 44 or 57-71. Metal chelates in which the metal species is Eu, Gd, Dy, Ho, Cr, Mn or Fe are especially preferred and Gd3 , Mn2 and Dy3 are particularly preferred. For such use, the paramagnetic metal species is conveniently non-radioactive as radioactivity is a characteristic which is neither required nor desirable for MR-diagnostics contrast agents. For use as X-ray or ultrasound contrast agenks, the chelated metal species is preferably a heavy metal species, for example a non-radioactive metal with an atomic number greater than 37, preferably greater than 50, e.g. Dy3 . For use in scintigraphy and radiotherapy, the chelated metal species must of course be radioactive and any conventional complexable radioactive metal isotope, such as 99mTc or lllIn for example, may be used. For radiography, the chelating agent may be in the form of a metal chelate with for example 67Cu, l53Sm or 90Y
For use in detoxification of heavy metals, the chelating agent must be in salt form with a physiologically acceptable counterion, e.g. sodium, calcium, ammonium, zinc or meglumine, e.g. as the sodium salt of the chelate of the compound of formula I with zinc or calcium.
Where the metal chelate carries an overall charge, such as is the case with the prior art Gd DTPA, it will conveniently be used in the form of a salt with a physiologically acceptable counterion, for example an a~monium, substituted ammonium, alkali metal or alkaline . . ~
.: ~
W092/11232 2 ~ P~T1~ 2~ t earth metal cation or an anion deriving from an inorganic or organic acid. In this regard, meglumine salts are particularly preferred.
Viewed from a further aspect, the present invention provides a diagnostic or therapeutic agent comprising a metal chelate, whereof the chelating entity is the residue of a compound of formula I or salt thereof, together with at least one pharmaceutical or veterinary carrier or excipient, or adapted for formulation therewith or for inclusion in a pharmaceutical formulation for human or veterinary use~
Viewed from another aspect, the present invention provides a detoxification agent comprising a chelatin~
agent according to the invention in the form of salt with a physiologically acceptable counterion, together with at least one pharmaceutical or veterinary carrier or excipient, or adapted for formulation therewith or for inclusion in a pharmaceutical formulation for human or veterinary use.
The diagnostic and therapeutic agents of the present invention may be formulated with conventional pharmaceutical or veterinary formulation aids, for example stabilizers, antioxidants, osmolality adjusting agents, buffers, pH adjusting agents, etc. and may be in a form suitable for parenteral or enteral administration, for example injection or infusion or administration directly into a body cavity having an external escape duct, for example the gastrointestinal tract, the ~ladder or the uterus. Thus the agent of the present invention may be in a conventional pharmaceutical administration form such as a tablet, capsule, powder, solution, suspension, dispersion, syrup, suppository, etc; however, solutions, suspensions and dispersions in physiologically acceptable carrier media, for example water for injections, will generally be pre~erred.
The compounds according to the invention may -. . , , . ~ ~ . . ~ ..................... . .
. . . :, , . ~ .:
W092/ll~32 2 0 9 o 7 ~ ~ PC~ 102468 therefore be formulated for administration using physiologically acceptable carriers or excipients in a manner fully within the skill of the art. For example, the compounds, optionally with the addition of pharmaceutically acceptable excipients, may be suspended or dissolved in an aqueous medium, with the resulting solution or suspension then being sterilized. Suitable additives include, for example, physiologically biocompatible buffers (as for example, tromethamine hydrochloride), additions ~e.g., O.Ol to lO mole percent) of chelants (such as, for example, DTPA, a DTPA-bisamide or non-complexed chelants of formula I) or calcium chelate complexes (as for example calcium DTPA~
CaNaDTPA-bisamide, calcium salts or chelates of chelants of formula I), or, optionally, additions (e.g., 1 to 50 mole percent) of calcium of sodium salts (for example, calcium chloride, calcium ascorbate, calcium gluconate or calcium lactate combined with metal chelate complexes of chelants formula I and the like).
If the compounds are to be formulated in suspension form, e.g., in water or physiological saline for oral administration, a small amount of soluble chelate ma~ be mixed with one or more of the inactive ingredients traditionally present in oral solutions and/or surfactants and/or aromatics for flavouring.
For MRI and for X-ray imaging of some portions of the bod~ the most preferred mode for administering metal chelates as contrast agents is parenteral, e.g., intravenous administration. Parenterally administrable forms, e.g., intra~enous solutions, should be sterile and free from physiologically unacceptable agents, and should have low osmolality to minimize irritation of other adverse effects upon administration, and thus the contrast medium should preferably be isotonic or slightly hypertonic. Suitable vehicles include aqueous vehicles customarily used for administering parenteral solutions such as Sodium Chloride Injection, Ringer's : , .: . ., - .. . . .
,; " ~:
WO 92/11232 2 ~ ~ s; r~ 3 ~E~
~,) A ~ : .
Injection, Dextrose Injection, Dextrose and Sodium Chloride Injection, Lactated Ringer's Injection and other solutions such as are described in Remingtonls Pharmaceutical Sciences, 15th ed., Easton: Mack Publishing Co., pp. 1405-1412 and 1461-1487 (1975) and The National Formulary XIV, 14th ed. Washington:
American Pharmaceutical Association (1975). The solutions can contain pre~ervatives, antimicrobial agents, buffers and antioxidants conventionally used for parenteral solutions, excipients and other additives which are compatible with the chelates and which will not interfere with the manufacture, storage or use of products.
Where the diagnostic or therapeutic agent comprises a chelate or salt of a toxic metal species, e.g. a heavy metal ion, it may be desirable to include within the formulation a slight excess of the chelating agent, e.g. as discussed by Schering in DE-A-3640708, or more preferably a slight excess of the calcium salt of such a chelating agent.
For MR-diagnostic examination, the diagnostic agent of the present invention, if in solution, suspension or dispersion form, will generally contain the metal chelate at concentration in the range 1 micromole to 1~5 mole per litre, preferably 0.1 to 700mM. The diagnostic agent may however be supplied in a more concentrated form for dilution prior to administration. The diagnostic agent of the invention may conveniently be administered in amounts of from 10 3 to 3 mmol of the metal species per kilogram of body weight, e.g. about mmol Gd/kg bodyweight.
For X-ray examination, the dose of the contrast agent should generally be higher and for scintigraphic examination the dose should generally be lower than for MR examination. For radiotherapy and detoxification, conventional dosages may be used.
Viewed from a further aspect, the present invention , , : ::,: ~ . , ; ., .: . , , . : . :, :~. . . . . . . .
W092/11232 PCT/E~ 2~
2~9~71~ ~ ~
- 1~ -provides a method of generating enhanced images of the human or non-human animal body, especiall~ the liver, which method comprises administering to said body a diagnostic agent according to the present invention and generating an X ray, MR-diagnostics, ultrasound or scintigraphic image of at least a part thereof.
Viewed from a further aspect, the present invention provides a method of radiotherapy practised on the human or non-human animal body, which method comprises administering to said body a chelate of a radioactive metal species with a chelating agent according to the invention.
Viewed from a further aspect, the present invention provides a method of heavy metal detoxification practised on the human or non-human animal body, which method comprises administering to said body a chelating agent according to the invention in the form of a salt with a physiologically acceptable counterion.
Viewed from a yet further aspect, the present invention also provides the use of the compounds, especially the metal chelates, according to the invention for the manufacture of diagnostic or therapeutic agents for use in methods of image generation, detoxification or radiotherapy practised on the human or non-human animal body.
Viewed from a still further aspect, the present invention provides a process for the preparation of the metal chelates of the invention which process comprises admixing in a solvent a compound of formula I or a salt te~g. the sodium salt) or chelate thereof together with an at least sparingly soluble compound of said metal, for example a chloride, oxide or carbonate.
Viewed from a yet still further aspect, the present invention provides a process for the preparation of the diagnostic or therapeutic agent of the present invention, which comprises admixing a metal chelate according to the invention, or a physiologically acceptable salt thereof, together with at least one : . , :,; .;.;, , .
W092/11232 2 ~ ~ 71 2 - 15 - !
pharmaceutical or veterinary carrier or excipient.
Viewed from a yet still further aspect, the present invention provides a process for the preparation of the detoxification agent of the invention, which comprises admixing a chelating agent according to the invention in the form of a salt with a physiologically acceptable counterion together with at least one pharmaceutical or veterinary carrier or excipient.
The disclosures of all of the documents mentioned herein are incorporated by reference.
The present invention will now be illustrated further by the following non-limiting Examples. All ratios and percentages given herein are by weight and all temperatures are in degrees Celsius unless otherwise indicated.
Example 1 3.6,9,12-Tetraaza-6,9-bis(carboxvmethyl)-4,11-dioxo-2,13-diphenvltetradecane EDTA-bis(anhydride) l.O g (3.9 mmol) was gradually added to a stirred solution of l-phenylethylamine 0.9 g (708 mmol) in dried acetonitrile (40 ml) at ambient temperature and under a nitrogen atmosphere. The solution was heated to reflux temperature (85C) and refluxed for 20 hours. The mixture was then cooled, and the precipitate which had formed was isolated by filtration and dried.
Yield 1.5g (77.1%), The crude solid was dissolved in 20 ml water to which was added lN NaOH to bring the pH to 10. After adjusting the pH with HCl (2N) to 3.5, the precipitate r formed was filtered off and dried, and the title compound was isolated.
Yield 1.06g (54.6%) Melting point: 187-l90~C.
WO~2/11232 2 ~ 9 ~ PC~ g~
Example 2 3,6,9.12,15-Pentaaza-6,9L12-tris(carboxymethYl~-4,14-dioxo-1,17-diPhenylheptadecane DTPA-bis(anhydride) l.0 g (2.8 mmol) was gradually added to a stirred solution of 2-phenylethylamine 0.68 g (5O6 mmol) in dried chloroform (85 ml) at ambient temperature. The stirred solution was left for 16 hours at ambient temperature. The precipitate which formed was isolated by filtration and dried. The crude product was then purified by reprecipitation as described in Example l.
Yield: 0.89 g (53 %) Melting point: 95-98C.
Example 3 2,5,8 ! 11, 14-Pentaaza-5,8,11-tris(carboxymethvl)-3,13 dioxo-1,15-bis(~Yrid-2-yl)pentadecane . . .
DTPA-bis(anhydride) l.0 g (2.8 mmol) was gradually added to a stirred solution of 2-aminomethylpyridine 0.61 g (5.6 mmol) in dried chloroform at ambient temperature.
The stirred solution was left for 42 hours at ambient temperature. The precipitate formed was isolated by filtration and dried~ `' Yield: 74.5%
Melting point: 107-110C.
Example 4 1,4,7,10,13-Pentaaza-4,7,10-triscarboxymethYl-2,12-dioxo-1,13_bis(N benzvl-piperidin-4-yl)tridecane DTPA-bis(anhydride) 1.0 g (2.8 mmol) was gradually added .,. . , . ., . . : , . . ~ .
-: ' , ,: ", ,' ', ', : ' `: ; ' ` : ' ' . ' ' .' .,'. . , : ' ,: ' , ' ` '' W092/1123Z 2 ~ 9 8 ~
to a stirred solution of 4-amino-1-benzylpiperidine 1.07 g (5.6 mmol) in dried chloroform (85 ml) at a~bient temperature. The solution was then heated to reflux temperature. The solution was refluxed with stirring overnight under a nitrogen atmosphere. The solution was then evaporated until 25-30 ml remained. ,~ubseque~tly ether (120ml) was added, and the precipitate was filtered off and dried.
Yield: 93.2g Example 5 1,4,7.10,13-Pentaaza-4,7,10-tris(carboxymethYl)-2,12-dioxo-1,13-bis(indan-2-ylLtridecane DTPA-bis(anhydride) 0.88 g (2.48 mmol) was gradually added to a stirred solution of 2-aminoindane 0.66 g (4.955 mmol) in dried acetonitrile (40 ml) at ambient temperature. The solution was heated to reflux temperature (85C) and refluxed under a nitrogen atmosphere ~or 4 hours. The reaction mixture was subsequently cooled, and the solution was decantedO T~e crude solid thereby obtained was dissolved in water with lN NaOH added to bring the pH to 13. After adjusting the pH with HC1 (lN) to 3.5, the precipitate formed was filtered off and dried.
Yield: 47.2%
Example 6 1,4,7 10-Tetraaza-4,7-bis(carboxymethyl)-2,9-dioxo 1,10-bis~indan-2-yl~decane EDTA-bis(anhydride) 0.38 g (1.46 mmol) was gradually added to a stirred solution of 2-aminoindane 0.39 g (2.93 mmol) in dried chloroform (30 ml) at ambient : .. - . .; .. ...
.
.. ,~
~. , : ~::
: ' ,, .. , ,: . , ' ~ ::
2~9.~ 2 WO92/~1232 P~ 8 temperature. After 24 hours the precipitate formed was isolated by filteration and dried. The crude product was then purified by reprecipitation as described in Example 1.
Yield: 0.43 g (56.4%) Melting point: 199.5-202C
Exam~le 7 2.5,8,11-Tetraaza-5,8-bis(carboxymethYl)-3,10-dioxo-1,12-diphenyldodecane EDTA-bis(anhydride) 1.0 g (3.9 mmol) was gradually added to a stirred solution of benzylamine 0.83 g (3.9 mmol) in dried chloroform (85 ml) at ambient temperature. The solution was heated to reflux temperature (70C) and refluxed under a nitrogen atmosphere for 19 hours. The reaction mixture was subsequently cooled, and the precipitate formed was filtered off and dried.
Yield: 1.69 g (92.09%) -Melting point: 139-141C
Example 8 1,4,7,10-Tetraaza-4,7-bis(carboxy~thvl)-2,9-dioxo-1,10 bis~Dvrid-2-yl)decane lg (3,9 mmol) EDTA-bis(anhydride) was gradually under stirring to acetonitrile (33 ml) heated to boiling. The mixture was refluxed for 1/2 h and 0.73g (1.1 mmol) 2-aminopyridine dissolved in 7 ml acetonitrile was gradually added.
The reaGtion mlxture was refluxed under nitrogen atmosphere for 40 hours, subsequently cooled to ambient temperature and the precipitate formed was filtered off .
. ., WO9~/ll232 2 ~ ~ ~ 712 PCT/EP9~/024~8 and dried.
Yield: 92.8%
Melting point: 215-217 C.
Exam~le 9 1,4,7,10,13-Pentaaza-4,7,10-tris(carboxy~ethYl)-2,12 dioxo-1.13-bis(N-benzYlpiperidin-4-yl)tridecane DTPA-bis(anhydride) 1.0 g ~2.8 mmol) was gradually added to a stirred solution of 4-amino-1-benzylpiperidine 1.07 g (5.6 mmol) in dried chloroform (100 ml) at ambient temperature. The stirred solution was left at ambient temperature for 66 hours. Then about 50% of the chloroform was evaporated off. Ether (50 ml) was then added, and the precipitate formed was filtered off and dried.
Yield: 92.8%
Example 10 ..
1,4.7,10-Tetraaza-4,7-bis~carboxvmethYl)-2,9-dioxo-1,10-bis(N-benzylpiperidin-4-yl)decane DTPA-bis(anhydride) 1.0 g (3.9 mmol) was gradually added to a stirred solution of 4-amino-1-benzylpiperidine 1.48 g (7.8 mmol? in dried chloroform (85 ml) at ambient temperature. The stirred solution was left for 18 hours at ambient temperature. The solution was evaporated until 25-30 ml remained. Subsequently ether (2 x 100 ml) was added. The precipitate formed was isolated by filtration and dried.
Yield: 91.9%
Melting point: 105-111C.
. .
. . ~
W092/11232 PCT/EP9~f~46~
2~8 ~ 1 2 Example 11 3,6,9,12-Tetraaza-6,9-bis(carboxymethyl)-4,11-dioxo-1,14-diphenvltetradecane EDTA~bis(anhydrïde) 1.0 g (3.9 mmol) was gradually added to a stirred solution of 2-phenylethylamine 0.9 g (7.8 mmol) in dried acetonitrile (40 ml) at ambient temperature under a nitrogen atmosphere. The solution was heated to reflux temperature (85C) and refluxed for 17 hours. The reaction mixture was subsequently cooled, and the precipitate formed was isolated by filtration and dried.
Yield: 1.7 g (87.8%) .....
ExamPle 12 .~
~i'`.` :
-- 1 ~ i CHELATING AGENTS
The present invention relates to chelat.in~ agents, more particularly aminopolycarboxylic acid chelants, and metal chelates thereof and the use of such chelating agents and chelates in diagnostic imaging, radiotherapy or heavy metal detoxification, and in particular as hepatobiliary contrast agents.
Medical uses of chelating agents are well established, for example as stabilizers for pharmaceutical preparations, as antidotes for poisonous heavy metal species and as agents for the administration, in chelate form, of metal ions for radiotherapy or diagnostic ima~ing, e.g. X-ray, magnetic resonance imaging (MRI), ultrasound or scintigraphy.
Aminopolycarboxylic acids and derivatives thereof (hereinafter referred to as APCAs) are well known as particularly effective chelants and are described in a wide range of publications, for example in US-A-2407645 (Bersworth), EP-A-71564 (Schering), EP-A-130934 (Schering), EP-A-165728 (Nycomed), US-A-4647447 (Schering), US-A-4826673 (Mallinckrodt), US-A-4639365 (Sherry), EP-A-26305s (Schering), EP-A-230893 (Bracco), EP-A-325762 (Bracco), WO-A-86/06605 (Lauffer), US-A-4746507 (Salutar), EP-A-290047 (Salutar), WO-A-90/01024 (Mallinckrodt), US-A-4687659 (Salutar) and EP-A-299795 (Nycomed) and in the documents cited in these patent publications.
Thus, for example, EP-A-71564 describes paramagnetic metal chelates, for which the chelating agent is nitrilotriacetic acid (NTA), N,N,N',N'-ethylenediaminetetraacetic acid (EDTA), N-hydroxyethyl-N,N',N'-ethylenediaminetriacetic acid (HEDTA), N,N,N',N",N"-diethylenetriaminepentaacetic acid (DTPA) and N-hydroxyethylimino-diacetic acid, as being suitable as contrast agents for MRI, contrast being .. .. : . , ~, . ........... . . ........... :~
:
WO~/11232 ~ ~ 9 ~ 7 12 PCT/E~Y~/0~46~
achieved by the effect of the magnetic field of the paramagnetic species (e.g. Gd(III)) with the chelatin~
agents serving to reduce the to~icity and to assist administration of the paramagnetic species.
Amongst the particular metal chelates disclosed by EP-A-71564 was -the dimeglumine salt of GdDTPA, the use of which as an MRI contrast agent has recently received much attention.
To improve stability, water solubility and selectivity, relative to the APCA chelating agents described in EP-A-71564, Schering in EP-A-130934 proposed the partial substitution for the N-attached carboxyalkyl groups of alkyl, alkoxyalkyl, alkoxycarbonylalkyl or alkylaminocarbonylalkyl groups, where any amide nitrogens may themselves carry polyhydroxy-alkyl ~roups.
For reduced toxicity, Salutar Inc, in for example US-A-4687659, has proposed the use as MRI contrast agents of chelates of paramagnetic metal ions and bisamides of DTPA, in particular DTPA-bismethylamide ~n the same patent, Salutar suggested that for imaging of the liver chelates of DTPA-bisthigher alkyl-amides) might be used.
In this field of hepatobiliary MRI contrast agents Nycomed, in EP-A-165728, have also proposed the use of paramagnetic chelates of certain anilide group-containing iminodiacetic acids and Lauffer in WO-A-86/0660S has suggested the use of paramagnetic chelates of various benzene ring containing chelants, e.g.
ethylene-bis-(2-hydroxyphenyl glycine) (EHPG), bist2-hydroxybenzyl)-ethylenediamine diacetic acid (HBED), benzo- and dibenzo-DTPA and triaza and tetraaza macrocycles which carry a fused benzene ring.
Still further APCA chelants for use in preparing MRI contrast agents have been proposed by Bracco in EP-A-230893 and EP-A-325762. These for the most par-t carry aryl or aralkyl substituents on the alkylene part of one - . ::, - ,. . :, , : .. ' :, ,.: . , . .: . - . . , WO92/11232 PCr/~ 6~
2 0 9 ~ ~J 1 ?
or more of the nitrogen-attached carboxyalkyl complex-forming moieties. Among the chelates covered is GdBOPTA, in which the chelant BOPTA has a DTPA structure with one N3 carboxymethyl replaced by a 2-benzyloxy-l-carboxy-ethyl group. GdBOPTA has been described by Vittadini et al in CMR '89, MRl9 as a liver~-specific ~RI
contrast agent.
Schering in EP-A-263059 have proposed a further range of DTPA and EDTA amide chelants for use in preparing MRI contrast agents. While commenting on the high lipophilicity of the DTPA-bisamides proposed by Salutar in WO-A-86/02841 (equivalent to US-A-4687659 discussed above), Schering have exemplified such compounds as GdDTPA-bispentylamide, GdDTPA-bisbutylamide and GdDTPA-phenylamide as well as chelates of further DTPA-alkylamides in which the alkyl moieties are substituted by hydrophilic groupings such as hydroxyl and alkoxy groups.
There is however a general and continuing need Eor APCA chelants which form metal chelates of reduced toxicity, improved stability, improved water solubility or improved biodistribution (e.g. enhanced tissue or organ specificity).
We now propose certain improved chela~ing agents, in particular amide derivatives of APCAs.
Viewed from one aspect therefore the invention provides chelants of formula I
HOOC CH2 ~ . ~ CH2COOH
NCH2CH2 [ NCH2CH2 ] nN ~ ( I ) R10CCH2 ~ CH2COR
(wherein n is 0 or l;
one group R1 is a group NR11R14 where R11 is a hydroxyl or alkoxy group or a group -L-Cy or -O-L-Cy, and R14 is a hydrogen atom, an alkyl group or a group -L-Cy, and the : . . ,. :: , :,. . , . :-W092/11232 PCT/E~ 2~
2~S7~2 other group R1 is a hydroxyl group or a group NR1lR14; L
is a bond or a straight-chain or branched saturated or unsaturated alkylene group optionally interrupted by a carbocyclic or heterocyclic saturated or unsa~urated group and optionally attached to the Cy group by a peptid~ or carbonyl link and optionally substituted ~y further Cy groups or by aminocarbonyl, acyl or acylamino groups; and Cy is a cyclic lipophilic group, eg a carbocyclic or heterocyclic saturated or unsaturated group itself optionally carrying one or more fused carbocyclic or heterocyclic saturated or unsaturated rings and optionally substituted by halogen atoms (eg iodine, chlorine or bromine), alkyl, al~ylamino, dialkylamino, carbamoyl, N-alkylcarbamoyl, acetamido, N-alkylacetamido and carbocyclic or heterocyclic saturated or unsaturated groups; with the provisos that in any NR11R14 group one of R11 and R14 group comprises a L-Cy group and that where n is 1 at least one R1 is other than phenylamine, benzylamine or methoxybenzylamine) and metal chelates and salts thereof.
Unless speci~ied otherwise, all alkyl or alkylene moieties in the compounds of the invention preferably contain up to ~0, particularly preferably up to 6, carbon atoms. The lipophilic Cy groups and the other cyclic rings in the compounds of formula I are particularly preferably mono or polycyclic groups containing 5 to 7 ring members in each ring, the rings if heterocyclic containing up to 3, preferably 1 or 2, non-adjacent ring heteroatoms selected from 0, N and S.
Preferred such rir.gs include benzene, pyridine, pyrimidine, pyrazine, 1,3-oxazine, 1,4-oxazine, 1,3-thiazine, 1,4-thiazine, pyrrole, imidazole, 1,3-oxazole, 1,3-thiazole, furan, thiophene, piperidine, piperazine, morpholine, perhydro-1,4-thiazine and pyrrolidine.
Thus particular examples of lipophilic Cy groups include groups of formula Ia to Ie , .: : . . :
; : ; :, . , ,., : :
.:. :: . .: :, :. , .: : , ~ :.
WO 92/11232 2 3 9 8 ~12 P~lER~ 2A68 ~;
R ~ R s ~:
R 3 ~ R 6 ~) y \~X "
R R7 ( I b) ( I c) , :
( la) /N
R 9 ( I d ) and other condensed a'cyclic rings (where R3 to R8 is each independently a bond or a hydrogen or halogen atom or an alkyl, alkylamino, .
dialkylamino, carbamoyl, N-alkylcarbamoyl, acetamido or N-alkylacetamido group or two adjacent groups from R3 to R8 together form a C25 alkylene or azaalkylene bridge, the point of attachment to L being a carbon of said bridge or one of said groups R3 to R8; X is nitrogen or CH and Y is CH or nitrogen; X' is CH2, NH, oxygen, sulphur or a bond; X" is nitrogen, oxygen or sulphur and Y" is CH or nitrogen; and R9 is a bond or hydrogen, alkyl or aralkyl, eg benzyl; such rings preferably not having ring heteroatoms at adjacent ring positions).
The linker moiety L is conveniently a branched or linear alkylene chain, eg such that LCy is of formula --(CHRt)k--(CO)a--(NR1)b-(CO)C--R10 where k is 0-10, especially 1 to 8, more especially 1 to ... ... . .. . . . . ..
WO9~tll232 PCT/E~
2~987 l2 ~
6; a, b and c are O or l, the sum of a and c being 0 or l; each R10 is a hydrogen atom, an alkyl group, an optionally esterified carboxyl group or a group Cy, at least one and preferably only one being a group Cy, and one or more CHR10 moieties may optionally be replaced by a 5-7 membered saturated homo or heterocyclic ring.
The carboxyl groups in the compounds of formula I
may, for example, be in the form of carboxylate salt groups, for example groups of formula -COOMt (where ~t is a monovalent cation or a fraction of a polyvalent cation, for example an ammonium or substituted ammonium ion or a metal ion, for example an alkali metal or alkaline earth metal ion). Particularly preferably, Mt is a cation deriving from an organic base, for example meglumine.
It is also particularly preferred that the number of the ion-forming carboxyl groups in the compounds of formula I be chosien to equal the valency of the me-tal species to be chelated by the compound of formula I.
Thus, for example, where Gd(III) i5 to be chelated, the chelating agent of formula I preferably contains three ion-forming -COOH or -COOM~ groups. In this way, the metal chelate will be formed as a neutral species, a form preferred since the osmotic pressures in concentrated solutions of such compounds are low and since their toxicities relative to their ionic analogues are significantly reduced.
Preferably the compounds of the invention contain two -L-Cy groups and particularly preferred compounds according to the invention include the chelants of formula II
A
HooccH2NCH2CH2 [NC~2CH2) n NCH2CH (II) R13NRlSCocH2 CH2COOH CH2coNR1sR13 (where n is 0 or l, R1s is hydrogen or methyl ., . : : : . :: :: , . . :: .:: :
WO~2/11232 2 0 9 ~ 7 1 2 PCTIEWI/0~68 and R13 is a group selected from benzyl, 2-phenyl-ethyl, 1-phenyl-ethyl, pyrid-4-yl, pyrid-3-yl, pyrid-2-yl, 3-morpholino-propyl, N-benzyl-piperidin-4-yl and inda~yl groups and iodinated such groups), and the metal chelates and salts thereof.
The chelant compounds of the invention may be prepared by amidation, eg analogously to EP-A-130934 (Schering~ and US-A-4687~59 (Salutar) of EDTA or DTPA or an activated or protected derivative thereof (eg an acid anhydride or bisanhydride) with an amine compound of formula III
HNR11'R14' (III) (where R11 and R14 are groups R11 and R14 as hereinbefore -defined or protected such groups), followed where necessary by deprotection.
As protecting groups, conventional protecting groups may be used, for example groups such as are described by T.W. Greene in "Protective Groups in Organic Synthesis", John Wiley & Sons, 1981.
Alternatively the compounds may be prepared in two or more stages, in the first reacting DTPA, EDTA or a derivative thereof to introduce one or two NR11 R14 groups (~here one of R11 and R14' is a group R11 or R1b and the other is a Cy-free analogues of R11 or R14) and in a second stage to introduce the Cy groups, eg by a peptide condensation reaction.
The amidation reactions are preferably performed in the liquid phase. Thus for example a solution of the amine in a solvent such as water, dipolar aprotic solvents, such as acetonitrile, N-methylpyrrolidone, N-methylmorpholine, dimethylformamide, dimethylacetamide, dimeth~vl sulfoxide, tetrahydrofuran and the like or mixtures thereof is prepared. The anhydride is added in portions or optionally dissolved in a dipolar aprotic anhydrous solvent such as acetonitrile, N-,, , .: ~ : . ;~, , . ~ . :
. .: :: :: . : , ~.:. :
:
WO92/11232 2 ~ 9 37 ~ 2 PCT/EP~ $ ~
methylpyrrolidone, N-methylmorpholine, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran and the like or mi~tures thereof. The reaction mixture is stirred under a nitrogen atmosphere for a period ranging between 0.5 hour and 3 days, preferably between l hour and 24 hoursO
The reaction temperatures generally range between about 0C and 100C, temperatures of about 20C to 80OC being preferred. For solvents with a low boiling point (l00C
or less) the reaction mixture can eventually be evaporated to dryness. For the solvents with higher boiling points, further solvents such as for example diethylether may be added and/or cooling may be used to precipitate the product.
Thus for example the bisamide chelants may be prepared by amidation as follows:
a) the amine of formula III is dissolved in a dry polar aprotic solvent, e.g. acetonitrile or chloroform, in a ratio of about l:l0 w:v amine:solvent. The bisanhydride of DTPA (or EDTA) (0.5 equivalents to the amine~ is added as dry powder in portions, with thorough stirring, and the reaction is allowed to proceed overnight. In the case of less reactive amines such as for example 2-aminopyridine, extensive refluxing may be necessary. In most cases the product precipitates from the reaction mixture and can be collected by filtration.
Otherwise the product can be precipitated by addition of diethyl ether and/or by cooling.
In the case of the bis-amides with non-heterocyclic side groups, the product may be puri~ied as follows: the precipitate from à) is dissolved in deionized water, and if necessary the pH is adjusted to 8-l0 using dilute NaOH. The pH is then adjus~ed to 3-3.5 with dilute HCl, and the precipitate is collected by filtration.
Chelants of formula I may be used as the basis for bifunctional chelants or for polychelant compounds, that ~. : , ... . ... .
', . . . ; . ~ .. , .. .,: :
WO92/11232 2 a ~ ~ 7 ~ /E~
' _ 9 _ :
is compounds containing several independent chelant groups, by substituting for a hydrogen atom or hydroxyl group a bond or linkage to a macromolecule or polymer~
e.g. a tissue specific biomolecule or a backhone polymer such as polylysine or polyethyleneimine which may carry several chelant groups and may itself be attached to a macromolecule to produce a bifunctional-polychelantO
Such macromelecular derivatives of the compounds of formula I and the salts and metal chelates t~ereof fo:~m a further aspect of the present invention. -The linkage of a compound of formula I to a macromolecule or backbone polymer may be effected by any of the conventional methods such as the carbodiimide method, the mixed anhydride procedure of Krejcarek et al. (see Biochemical and Biophysical Research Communications 77: 581 (1977)), the cyclic anhydride method of Hnatowich et al. (see Science 220: 613 (1983) and elsewhere), the backbone conjugation techniques oE
Meares et al. (see Anal. Biochem. 142: 68 (1984) and elsewhere) and Schering (see EP-A-331616 for example) and by the use of linker molecules as describéd for example by Nycomed in W0-A-89/06979.
Formation of salts and chelates of the chelants of the invention may again be performed in a conventional manner.
The chelating agents of the present invention are particularly suitable for use in detoxification or in the formation of me~al chelates, chelates which may be used for example in or as contrast agents for in vivo or in vitro magnetic resonance (MX), X-ray or ultrasound diagnostics (e.g~ MR imaging and MR spectroscopy), or scintigraphy or in or as therapeutic agents for radiotherapy, and such metal chelates form a particularly important embodiment of the present invention.
Salts or chelate comple~es of the compounds of the invention containing heavy metal ions are particularly : . . . : , ., - . . : . . ., , ~ , :
WO92/11232 PCT/EP~ 2~
2 ~ ~ r~ g 2 1~ 1 ) useful in diagnostic imaging or therapy. Especially preferred are salts or complexes with metals of atomic numbers 20-32, 42 44, 49 and 57 to 83, particularly Gd, Dy and Yb.
For use as an MR-diagnostics contrast agent, the chelated metal ion is particularly suitably a paramagnetic ion, the metal conveniently bein~ a transition metal or a lanthanide, preferably having an atomic number of 21-29, 42, 44 or 57-71. Metal chelates in which the metal species is Eu, Gd, Dy, Ho, Cr, Mn or Fe are especially preferred and Gd3 , Mn2 and Dy3 are particularly preferred. For such use, the paramagnetic metal species is conveniently non-radioactive as radioactivity is a characteristic which is neither required nor desirable for MR-diagnostics contrast agents. For use as X-ray or ultrasound contrast agenks, the chelated metal species is preferably a heavy metal species, for example a non-radioactive metal with an atomic number greater than 37, preferably greater than 50, e.g. Dy3 . For use in scintigraphy and radiotherapy, the chelated metal species must of course be radioactive and any conventional complexable radioactive metal isotope, such as 99mTc or lllIn for example, may be used. For radiography, the chelating agent may be in the form of a metal chelate with for example 67Cu, l53Sm or 90Y
For use in detoxification of heavy metals, the chelating agent must be in salt form with a physiologically acceptable counterion, e.g. sodium, calcium, ammonium, zinc or meglumine, e.g. as the sodium salt of the chelate of the compound of formula I with zinc or calcium.
Where the metal chelate carries an overall charge, such as is the case with the prior art Gd DTPA, it will conveniently be used in the form of a salt with a physiologically acceptable counterion, for example an a~monium, substituted ammonium, alkali metal or alkaline . . ~
.: ~
W092/11232 2 ~ P~T1~ 2~ t earth metal cation or an anion deriving from an inorganic or organic acid. In this regard, meglumine salts are particularly preferred.
Viewed from a further aspect, the present invention provides a diagnostic or therapeutic agent comprising a metal chelate, whereof the chelating entity is the residue of a compound of formula I or salt thereof, together with at least one pharmaceutical or veterinary carrier or excipient, or adapted for formulation therewith or for inclusion in a pharmaceutical formulation for human or veterinary use~
Viewed from another aspect, the present invention provides a detoxification agent comprising a chelatin~
agent according to the invention in the form of salt with a physiologically acceptable counterion, together with at least one pharmaceutical or veterinary carrier or excipient, or adapted for formulation therewith or for inclusion in a pharmaceutical formulation for human or veterinary use.
The diagnostic and therapeutic agents of the present invention may be formulated with conventional pharmaceutical or veterinary formulation aids, for example stabilizers, antioxidants, osmolality adjusting agents, buffers, pH adjusting agents, etc. and may be in a form suitable for parenteral or enteral administration, for example injection or infusion or administration directly into a body cavity having an external escape duct, for example the gastrointestinal tract, the ~ladder or the uterus. Thus the agent of the present invention may be in a conventional pharmaceutical administration form such as a tablet, capsule, powder, solution, suspension, dispersion, syrup, suppository, etc; however, solutions, suspensions and dispersions in physiologically acceptable carrier media, for example water for injections, will generally be pre~erred.
The compounds according to the invention may -. . , , . ~ ~ . . ~ ..................... . .
. . . :, , . ~ .:
W092/ll~32 2 0 9 o 7 ~ ~ PC~ 102468 therefore be formulated for administration using physiologically acceptable carriers or excipients in a manner fully within the skill of the art. For example, the compounds, optionally with the addition of pharmaceutically acceptable excipients, may be suspended or dissolved in an aqueous medium, with the resulting solution or suspension then being sterilized. Suitable additives include, for example, physiologically biocompatible buffers (as for example, tromethamine hydrochloride), additions ~e.g., O.Ol to lO mole percent) of chelants (such as, for example, DTPA, a DTPA-bisamide or non-complexed chelants of formula I) or calcium chelate complexes (as for example calcium DTPA~
CaNaDTPA-bisamide, calcium salts or chelates of chelants of formula I), or, optionally, additions (e.g., 1 to 50 mole percent) of calcium of sodium salts (for example, calcium chloride, calcium ascorbate, calcium gluconate or calcium lactate combined with metal chelate complexes of chelants formula I and the like).
If the compounds are to be formulated in suspension form, e.g., in water or physiological saline for oral administration, a small amount of soluble chelate ma~ be mixed with one or more of the inactive ingredients traditionally present in oral solutions and/or surfactants and/or aromatics for flavouring.
For MRI and for X-ray imaging of some portions of the bod~ the most preferred mode for administering metal chelates as contrast agents is parenteral, e.g., intravenous administration. Parenterally administrable forms, e.g., intra~enous solutions, should be sterile and free from physiologically unacceptable agents, and should have low osmolality to minimize irritation of other adverse effects upon administration, and thus the contrast medium should preferably be isotonic or slightly hypertonic. Suitable vehicles include aqueous vehicles customarily used for administering parenteral solutions such as Sodium Chloride Injection, Ringer's : , .: . ., - .. . . .
,; " ~:
WO 92/11232 2 ~ ~ s; r~ 3 ~E~
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Injection, Dextrose Injection, Dextrose and Sodium Chloride Injection, Lactated Ringer's Injection and other solutions such as are described in Remingtonls Pharmaceutical Sciences, 15th ed., Easton: Mack Publishing Co., pp. 1405-1412 and 1461-1487 (1975) and The National Formulary XIV, 14th ed. Washington:
American Pharmaceutical Association (1975). The solutions can contain pre~ervatives, antimicrobial agents, buffers and antioxidants conventionally used for parenteral solutions, excipients and other additives which are compatible with the chelates and which will not interfere with the manufacture, storage or use of products.
Where the diagnostic or therapeutic agent comprises a chelate or salt of a toxic metal species, e.g. a heavy metal ion, it may be desirable to include within the formulation a slight excess of the chelating agent, e.g. as discussed by Schering in DE-A-3640708, or more preferably a slight excess of the calcium salt of such a chelating agent.
For MR-diagnostic examination, the diagnostic agent of the present invention, if in solution, suspension or dispersion form, will generally contain the metal chelate at concentration in the range 1 micromole to 1~5 mole per litre, preferably 0.1 to 700mM. The diagnostic agent may however be supplied in a more concentrated form for dilution prior to administration. The diagnostic agent of the invention may conveniently be administered in amounts of from 10 3 to 3 mmol of the metal species per kilogram of body weight, e.g. about mmol Gd/kg bodyweight.
For X-ray examination, the dose of the contrast agent should generally be higher and for scintigraphic examination the dose should generally be lower than for MR examination. For radiotherapy and detoxification, conventional dosages may be used.
Viewed from a further aspect, the present invention , , : ::,: ~ . , ; ., .: . , , . : . :, :~. . . . . . . .
W092/11232 PCT/E~ 2~
2~9~71~ ~ ~
- 1~ -provides a method of generating enhanced images of the human or non-human animal body, especiall~ the liver, which method comprises administering to said body a diagnostic agent according to the present invention and generating an X ray, MR-diagnostics, ultrasound or scintigraphic image of at least a part thereof.
Viewed from a further aspect, the present invention provides a method of radiotherapy practised on the human or non-human animal body, which method comprises administering to said body a chelate of a radioactive metal species with a chelating agent according to the invention.
Viewed from a further aspect, the present invention provides a method of heavy metal detoxification practised on the human or non-human animal body, which method comprises administering to said body a chelating agent according to the invention in the form of a salt with a physiologically acceptable counterion.
Viewed from a yet further aspect, the present invention also provides the use of the compounds, especially the metal chelates, according to the invention for the manufacture of diagnostic or therapeutic agents for use in methods of image generation, detoxification or radiotherapy practised on the human or non-human animal body.
Viewed from a still further aspect, the present invention provides a process for the preparation of the metal chelates of the invention which process comprises admixing in a solvent a compound of formula I or a salt te~g. the sodium salt) or chelate thereof together with an at least sparingly soluble compound of said metal, for example a chloride, oxide or carbonate.
Viewed from a yet still further aspect, the present invention provides a process for the preparation of the diagnostic or therapeutic agent of the present invention, which comprises admixing a metal chelate according to the invention, or a physiologically acceptable salt thereof, together with at least one : . , :,; .;.;, , .
W092/11232 2 ~ ~ 71 2 - 15 - !
pharmaceutical or veterinary carrier or excipient.
Viewed from a yet still further aspect, the present invention provides a process for the preparation of the detoxification agent of the invention, which comprises admixing a chelating agent according to the invention in the form of a salt with a physiologically acceptable counterion together with at least one pharmaceutical or veterinary carrier or excipient.
The disclosures of all of the documents mentioned herein are incorporated by reference.
The present invention will now be illustrated further by the following non-limiting Examples. All ratios and percentages given herein are by weight and all temperatures are in degrees Celsius unless otherwise indicated.
Example 1 3.6,9,12-Tetraaza-6,9-bis(carboxvmethyl)-4,11-dioxo-2,13-diphenvltetradecane EDTA-bis(anhydride) l.O g (3.9 mmol) was gradually added to a stirred solution of l-phenylethylamine 0.9 g (708 mmol) in dried acetonitrile (40 ml) at ambient temperature and under a nitrogen atmosphere. The solution was heated to reflux temperature (85C) and refluxed for 20 hours. The mixture was then cooled, and the precipitate which had formed was isolated by filtration and dried.
Yield 1.5g (77.1%), The crude solid was dissolved in 20 ml water to which was added lN NaOH to bring the pH to 10. After adjusting the pH with HCl (2N) to 3.5, the precipitate r formed was filtered off and dried, and the title compound was isolated.
Yield 1.06g (54.6%) Melting point: 187-l90~C.
WO~2/11232 2 ~ 9 ~ PC~ g~
Example 2 3,6,9.12,15-Pentaaza-6,9L12-tris(carboxymethYl~-4,14-dioxo-1,17-diPhenylheptadecane DTPA-bis(anhydride) l.0 g (2.8 mmol) was gradually added to a stirred solution of 2-phenylethylamine 0.68 g (5O6 mmol) in dried chloroform (85 ml) at ambient temperature. The stirred solution was left for 16 hours at ambient temperature. The precipitate which formed was isolated by filtration and dried. The crude product was then purified by reprecipitation as described in Example l.
Yield: 0.89 g (53 %) Melting point: 95-98C.
Example 3 2,5,8 ! 11, 14-Pentaaza-5,8,11-tris(carboxymethvl)-3,13 dioxo-1,15-bis(~Yrid-2-yl)pentadecane . . .
DTPA-bis(anhydride) l.0 g (2.8 mmol) was gradually added to a stirred solution of 2-aminomethylpyridine 0.61 g (5.6 mmol) in dried chloroform at ambient temperature.
The stirred solution was left for 42 hours at ambient temperature. The precipitate formed was isolated by filtration and dried~ `' Yield: 74.5%
Melting point: 107-110C.
Example 4 1,4,7,10,13-Pentaaza-4,7,10-triscarboxymethYl-2,12-dioxo-1,13_bis(N benzvl-piperidin-4-yl)tridecane DTPA-bis(anhydride) 1.0 g (2.8 mmol) was gradually added .,. . , . ., . . : , . . ~ .
-: ' , ,: ", ,' ', ', : ' `: ; ' ` : ' ' . ' ' .' .,'. . , : ' ,: ' , ' ` '' W092/1123Z 2 ~ 9 8 ~
to a stirred solution of 4-amino-1-benzylpiperidine 1.07 g (5.6 mmol) in dried chloroform (85 ml) at a~bient temperature. The solution was then heated to reflux temperature. The solution was refluxed with stirring overnight under a nitrogen atmosphere. The solution was then evaporated until 25-30 ml remained. ,~ubseque~tly ether (120ml) was added, and the precipitate was filtered off and dried.
Yield: 93.2g Example 5 1,4,7.10,13-Pentaaza-4,7,10-tris(carboxymethYl)-2,12-dioxo-1,13-bis(indan-2-ylLtridecane DTPA-bis(anhydride) 0.88 g (2.48 mmol) was gradually added to a stirred solution of 2-aminoindane 0.66 g (4.955 mmol) in dried acetonitrile (40 ml) at ambient temperature. The solution was heated to reflux temperature (85C) and refluxed under a nitrogen atmosphere ~or 4 hours. The reaction mixture was subsequently cooled, and the solution was decantedO T~e crude solid thereby obtained was dissolved in water with lN NaOH added to bring the pH to 13. After adjusting the pH with HC1 (lN) to 3.5, the precipitate formed was filtered off and dried.
Yield: 47.2%
Example 6 1,4,7 10-Tetraaza-4,7-bis(carboxymethyl)-2,9-dioxo 1,10-bis~indan-2-yl~decane EDTA-bis(anhydride) 0.38 g (1.46 mmol) was gradually added to a stirred solution of 2-aminoindane 0.39 g (2.93 mmol) in dried chloroform (30 ml) at ambient : .. - . .; .. ...
.
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: ' ,, .. , ,: . , ' ~ ::
2~9.~ 2 WO92/~1232 P~ 8 temperature. After 24 hours the precipitate formed was isolated by filteration and dried. The crude product was then purified by reprecipitation as described in Example 1.
Yield: 0.43 g (56.4%) Melting point: 199.5-202C
Exam~le 7 2.5,8,11-Tetraaza-5,8-bis(carboxymethYl)-3,10-dioxo-1,12-diphenyldodecane EDTA-bis(anhydride) 1.0 g (3.9 mmol) was gradually added to a stirred solution of benzylamine 0.83 g (3.9 mmol) in dried chloroform (85 ml) at ambient temperature. The solution was heated to reflux temperature (70C) and refluxed under a nitrogen atmosphere for 19 hours. The reaction mixture was subsequently cooled, and the precipitate formed was filtered off and dried.
Yield: 1.69 g (92.09%) -Melting point: 139-141C
Example 8 1,4,7,10-Tetraaza-4,7-bis(carboxy~thvl)-2,9-dioxo-1,10 bis~Dvrid-2-yl)decane lg (3,9 mmol) EDTA-bis(anhydride) was gradually under stirring to acetonitrile (33 ml) heated to boiling. The mixture was refluxed for 1/2 h and 0.73g (1.1 mmol) 2-aminopyridine dissolved in 7 ml acetonitrile was gradually added.
The reaGtion mlxture was refluxed under nitrogen atmosphere for 40 hours, subsequently cooled to ambient temperature and the precipitate formed was filtered off .
. ., WO9~/ll232 2 ~ ~ ~ 712 PCT/EP9~/024~8 and dried.
Yield: 92.8%
Melting point: 215-217 C.
Exam~le 9 1,4,7,10,13-Pentaaza-4,7,10-tris(carboxy~ethYl)-2,12 dioxo-1.13-bis(N-benzYlpiperidin-4-yl)tridecane DTPA-bis(anhydride) 1.0 g ~2.8 mmol) was gradually added to a stirred solution of 4-amino-1-benzylpiperidine 1.07 g (5.6 mmol) in dried chloroform (100 ml) at ambient temperature. The stirred solution was left at ambient temperature for 66 hours. Then about 50% of the chloroform was evaporated off. Ether (50 ml) was then added, and the precipitate formed was filtered off and dried.
Yield: 92.8%
Example 10 ..
1,4.7,10-Tetraaza-4,7-bis~carboxvmethYl)-2,9-dioxo-1,10-bis(N-benzylpiperidin-4-yl)decane DTPA-bis(anhydride) 1.0 g (3.9 mmol) was gradually added to a stirred solution of 4-amino-1-benzylpiperidine 1.48 g (7.8 mmol? in dried chloroform (85 ml) at ambient temperature. The stirred solution was left for 18 hours at ambient temperature. The solution was evaporated until 25-30 ml remained. Subsequently ether (2 x 100 ml) was added. The precipitate formed was isolated by filtration and dried.
Yield: 91.9%
Melting point: 105-111C.
. .
. . ~
W092/11232 PCT/EP9~f~46~
2~8 ~ 1 2 Example 11 3,6,9,12-Tetraaza-6,9-bis(carboxymethyl)-4,11-dioxo-1,14-diphenvltetradecane EDTA~bis(anhydrïde) 1.0 g (3.9 mmol) was gradually added to a stirred solution of 2-phenylethylamine 0.9 g (7.8 mmol) in dried acetonitrile (40 ml) at ambient temperature under a nitrogen atmosphere. The solution was heated to reflux temperature (85C) and refluxed for 17 hours. The reaction mixture was subsequently cooled, and the precipitate formed was isolated by filtration and dried.
Yield: 1.7 g (87.8%) .....
ExamPle 12 .~
4.7,10.13,16-Pentaaza-7,10,13-tris(carboxymethYl)-5,15-dioxo-l,19-bis(morpholino)nonadecane DTPA-bis(anhydride) 1.0 g (2.8 mmol) was gradually added to a stirred solution of N-(3-aminopropyl)morpholine 0.81 g (5.6 mmol) in dried chloroform (85 ml) at ambient temperature. The solution was stirred for 27 hours and then refluxed under a nitrogen atmosphere for 69 hours.
The solution was evaporated until 25-30 ml remained.
Subsequently ether (12Oml) was added, The precipitate formed was isolated by filtration and dried.
Yield: 93.9%
ExamDle 13 2.5,8,11,14-Pentaaza-5,8,11-tris(carboxymethyl)-3,15-dioxo-1,15-bis(pYrid-3-yl~pentadecane DTPA-bis(anhydride) 1.0 g (2.8 mmol) was gradually added . , , ................... . : ~
, .. ..
.
WO92/11232 2~9~712 ~f`~51/~'~,6~ 1 to a stirred solution of 3-aminomethylpyridine 0.61 g (5.6 mmol) in dried acetonitrile (40 ml) at ambient temperature. The solution was stirred for 84 hours~
The precipitate formed was isolated by filtration and dried.
Yield: 87.6%
ExamPle 14 2,5,8,11-Tetraaza-5~8-bis(carboxymethyl)-3,10-dioxo~
1.12- bis(pyrid-3-yl~dodecane EDTA-bis(anhydride) 1.0 g (3.9 mmol) was gradually added to a stirred solution of 3-aminomethylpyridine 0.84 g (7.8 mmol) in dried chloroform (85 ml) at ambient temperature. The precipitate formed was isolated b~
filtration and dried.
Yield: 97.8% ' Melting point: 212-216C
Example 15 2,5.8,11-Tetraaza-5,8-bis(carboxymethyl)-3.10-dioxo-1,12- bisrpyrid-2-yl)dodecane EDTA-bis(anhydride) 1.0 g (3.9 mmol) was gradually added to a stirred solution of 2-aminomethylpyridine 0.84 g (7.8 mmol) in dried chloroform (120 ml) at ambient temperature. The stirred solution was left for 16 hours at ambient temperature. The solution was evaporated until 25-30 ml remained. Subsequently ether (50 ml) was added. The precipitate formed was isolated by filteration and dried.
Yield: 98.4%
Melting point: 73-81C.
.
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WO92/11232 2 ~ 9 8 .~ ~ 2 PCT/EP9~ 4~ ~
Example 16 3,6 9 12-Tetraaza-2 13-bis(benzyloxycarbonyl)-6,9-bis(carboxymethyl)-4~11-dioxo-1~14-diPhenyltetradecane EDTA-bis(anhydride) (0.4 g, 1.56 mmol) was added in portions to a solution of H-Phe-OBzl-HCl (0.91 g, 3.12 mmol) and triethylamine (0.32 g, 3.12 mmol) in chloroform (50 ml). The reaction mixture was stirred at ambient temperature for 20 hours before the white precipitated product was collected by filtration and dried under vacuum at 50C.
Yield: 0.83 g (69%), Melting point: 174-178C
Elemental analysis:
calculated: C 65.78 H 6.05, N 7.30 found: C 65.53, H 6.15, N 7.14 1H NMR (DMSO): ~ 8.32 (d, J 8.06 Hz, 2H), 7.5-7.08 (m, 20H), 5.10 (s, 4H), 4.70-4.50 (m, 2H), 3.50-2.41 (m, 16H).
Example l?
3,6,9 r 12 15-Pentaaza-2 16-bis(benzyloxycarbonyl)-6,9.12-tris(carboxymethyl)-4,14-dioxo-1 17-diPhenylhe~tadecane DTPA-bis(anhydride) (0.56 g, 1.56 mmol) was added in portions to a solution of H-Phe-OBzl-HCl (0.91 g, 3.12 mmol) and triethylamine (0.32 g, 3.12 mmol) in chloroform (50 ml). The reaction mixture was refluxed under N2 for 24 hours before the white precipitated product was collected by filtration and dried under vacuum at 50~C.
Yield: 1.1 g (81%), Melting point: 120-126C
1H NMR (DMSO): ~ 8.45 (d, J 7.78 Hz, 2H), 7.50-7.05 (m, 20H), 5.10 (s, 4H), 4.70 4.50 (m, 2H), 3.70-2.60 (m, . ' :, .' ' , ' .,' -.
W092/11232 2~ 7~ PCT/~ 2~$
22H).
.
Example 18 3.6 9.12-Tetraaza-2.13_dicarboxY 6.9-bislcarbQxYmethy 4.11-dioxo-1,14-diPhenyltetradecane LioH tO.34 g, 14.3 mmol) was added to a suspension of EDTA-bis(benzylphenylalanyl)amide (1.1 g, 1.43 mmol) in a mixture of methanol/water (3:1, 44 ml). After 2 hours the TLC showed that the hydrolysis was completed.
Methanol was removed under reduced pressure and the reaction mixture acidified to pH 3.5 with 2N HCl. The product was collected by filtration and dried under '~
vacuum at 50C.
Yield: 0.89 g, Melting point: 115-120C
H NMR (DMSO): ~ 8.22 (d, J 7.4 Hz, 2H), 7.50-7.08 (mr 1 OH), 4.61-4.35 (m, 2H), 3.40-2.40 (m, 16H).
Example 19 3.6 9,12 15-Pentaaza-2 16-dicarboxy-6 9.12-tris(carboxymethvl)-4 14-dioxo-1 17-diphen~lheptadecane LioH (0.30 g, 12.7 mmol) was added to a suspension of DTPA-bis(benzylphenylalanyl)amide (1.1 g, 1.27 mmol) in a mixture of methanol/water (3:1, 44 ml). After 2 hours the TLC showed that the hydrolysis was completed. The solvent was removed under reduced pressure and the residue dried under vacuum at 50C to give l.Q4 g of crude product.
1H NMR (DMSO): ~ 8.49 (d, J 1.6 Hz, 2H), 7.40-7.00 (m, 1 OH), 4.43-4.20 (m, 2H), 3.61-2.55 (m, 22H).
: ::~ :. . . , ,: . ,, WO9-/llZ32 2 0 9 ~ 7 12 PC~/EP9~/~246~ l ExamPle 20 3 ! 6,9,12-Tetraaza-6,9-bis(carboxYmethYl)-4,11-dioxo-1,14-bis(pyrid-2-YlLtetradecane A solution of 2-(2-aminoethyl)pyridine (0.95 g, 7O8 mmol) and EDTA-bis(anhydride) (1.0 g, 3.9 mmol) in 85 ml .
chloroform was stirred for 4 days at ambient temperature. Most of the chloroform was evaporatedO
The rest (20-30 ml) was dissolved in 100 ml diethylether to crystallize. The solid product was collected and dried under reduced pressure to yield 88% product.
Melting point: 60-64OC
Elemental analysis:
Calculated: C 56.05 H 6.25 Found: C 55.88 H 6.25 lH NMR (200 MHz DMSO-d6) ~ ppm: 2.66 (s, 4H, t, 4H, J =
7.1 Hz), 3.20 (s, 4H), 3.33 (s, 4H), 3.4-4.6 (m, 4H), 7.1-7.3 (m, 4H), 7.6-7.8 (m, 2H), 8.10 (t, 2H, 5.7 Hz), 8.50 (d, 2H, J = 4.7 Hz).
Exam~le 21 3.6.9 12 15-Pentaaza-6 ~9 12-trisrcarboxYmethY1)-4.14-dioxo-1 17-bis(PYrid-2-vl)heptadecane 2-(2-Aminoethyl)pyridine (0.68 g, 5.6 mmol) and DTPA-bis(anhydride) (1.0 g, 2.8 mmol) were dissolved in 85 ml chloroform. The mixture was stirred for 22 hours at ambient temperature. The solid product was separated from the solution by filtration before being dried in vacuum to give 56% product.
Melting point: 110-118C
Elemental analysis:
Calculated: C 53.36 H 6.18 Found: C 57.58 H 6.46 1H NMR (200 MHz DMSO-d6) ~ ppm: 2.8-3.8 (m, 30H), 7.1-7.4 ' ;' '. ~ ~: , " ' ;
'., . ;'' . ' ;' ', : '. ', ':
`
W092/1123Z PC~/EI~
2 ~ 2 (m, 4H), 7.6-7.8 (m, 2H), 8.1-8.3 (m, 2H), 8.49 (d, 2H, 4.8 Hz).
ExamPle 22 3,6 9~12-Tetraaza-2 13-dicarboxv-6,9-bis~carboxvmet~yl~ ¦
4.11-dioxo-1 14-bis(indol-3-vl~tetradecane Triethylamine (On39 g, 3.9 mmol), tryptophanmethylester (HCl) and EDTA-bis(anhydride~ (0.5 g, 1.95 mmol) were dissolved in 70 ml chloroform. The suspension was stirred for 21 hours at ambient temperature. The solid product was collected by filtration and dried in vacuum to give 83~ yield.
Melting point: 84-91C
Elemental analysis: ~ -Calculated: C 53.30 H ~.46 Found: C 58.94 H 5.83 H NMR (200 MHz DMSO-d6) ~ ppm: 2.26 (3, 4H), 3.0-304 (m 14H), 3.60 (s, 6H), 4.5-4.7 (m, 2H), 6.95-7.15 (m, 4H)~
7.19 (d, 2H, J = 1.8 Hz), 7.37 (d, 2H, J = 7.5 Hz), 7052 (d, 2H, 7.7 Hz), 8.27 (d, 2H, J = 7.7 Hz).
Example 23 3 6 9~12-Pentaaza-2 16-dicarboxv-6 9~12-tris(carboxYmeth~1)-4 14-dioxo-1 17-bis(indol-3-yl)heptadecane Triethylamine (0.57 g, 5.6 mmol), tryptophanmethylester (HCl) (1.43 g, 5.6 mmol) and DTPA-bis(anhydride) (1.000 g, 2.8 mmol) were dissolved in 100 ml chloroform. The mixture was refluxed in a nitrogen atmosphere for 3 days. Most of the chloroform was removed ~20-30 ml left). 100 ml diethylether was added to the concentrated solution. The crystalline product was '; ` ; -. , i , : !
WO92/11232 PCT/EP9FI/~2468 2~7 ~ 2, collected by filtration, dissolved in basic aqueous solution and recrystallized with 0.5 M HCl.
The identity of the product as the title compound was verified by 1H and 13C NMR.
Example 24 3,6.9,12-Tetraaza-2,13-bis(methvloxYcarbonyll-6,9 bis(carboxymeth~l~4,11-dioxo-1,14-bis(indol-3-Yl)tetradecane Lithium hydroxide (14.4 mg, 0.61 mmol) was dissolved in a 4.5 ml mixture of MeOH/H2O(3:1). 3,6,9,12-Tetraaza~
2,13,-bis(methyloxycarbonyl)-6,9-bis(carboxymethyl)-4,11-dioxo-1,14-bis(indol-3-yl)tetradecane (60.0 mg, 8.7 x 102 mmol) was added and the solution was stirred for 8 hours. Methanol was removed, 2 ml water was added and the pH was adjusted to 3.5 (0.5 M HCl). The solid product was collected and dried in vacuo for 12 hoursO
The identity of the product as the title compound was verified by lH NMR.
Exam~le 25 3.6,9,12,15-Pentaaza-2 16-bis(methYloxYcarbonYl)-6.9.12-tris(carboxymethyl) 4,14-dioxo-1 17-bis(indol-3-vl)heptadecane Lithium hydroxide (0.32 g, 13.4 mmol) was dissolved in a mixture of MeOH/H2O(3:l). 3,6,9,12,15-Pentaaza-2,16,-bis(methyloxycarbonyl)-6,s,12-tris(carboxymethyl)-4,14-dioxo-1,17-bis(indol-3-yl)heptadecane (1.33 g, 1.67 mmol~ was added and the solution was stirred for 6 hours at ambient temperature. Methanol was evaporated and 10 ml water was added to the residual. The pH was adjusted to 3.5 with 0.5 M HCl. The solid product was collected , ', .: , . ; .: :-.: ~:.
WO92/11232 ~ 6~i 1 2 r by filtration and dried to give 18% product.
Melting point: 158-160C
Elemental analysis:
Calculated: C 55.86 H 5.80 Found: C 56.45 H 5.67 1H NMR (200 MHz, DMSO-d6) ~ ppm: 2.5-3.6 (m, 22H), 4 4~
4.7 (m, 2H), 6.9-7.2 (m, 4H), 7.22 (s, 2H), 7.36 (d, 2H, J = 7.5 Hz), 7.56 (d, 2H, J = 7.4 Hz), 8.27 (d, 2H, J =
8.1 Hz).
Example 26 General procedure for complexation w:ith Gadolinium (20 mM solution) GdCl3 (1 mmol) in 4 ml water was dropwise added to a solution of a chelant of formula I (where n is 1) (1 mmol) in 30 ml water, while the pH was kept at 5-6 by adding 1 N NaOH. After addition the mixture was stirred for 1/2 hour and diluted with water to 50 ml.
Exam~le 27 General ~rocedure for complexation with Man~anese (50 mM
solution) MnCl2 (1.25 mmol) in 3 ml water was dropwise added to a solution of a chelant of formula I (where n is 0) (1.25 mmol) in 15 ml water, while the pH was kept at 5-6 by adding lN NaOH. After addition the mixture was stirred for 1/2 hour and diluted with water to 25 ml.
:. , ~' ~' , :' wO g2/1l232 2 0 9 ~ 7 ~ ~ PCT/EP91/02468 r .
Example 28 Relaxivitv of Gd and Mn chelates in water and AutonormR
measured at 37'C, 20 MHz on an IBM PC/20 Series NMR
Analyzer (Minispec).
I _ . .' Water AutonormR
Chela~ing agent Metal l , (Example No.) _ rl (mM'' s'') r2 (mM'' s'') r1 (mM'~ s' ) ¦ :
1 Mn 3.3 2.8 2 Gd 3.4 5.8 _ 7.0 ¦ .
3 Gd 4.6 3.9 6.0 4 Gd 4.3 7.2 7.5 7 Mn 3.7 2.6 Mn 5.4 1.5 11 _ Mn 3.9 3.3 12 Gd 3.7 6.5 6.3 ~:
j 13 Gd 3.2 5.9 5.9 14 Mn 3.4 1 3.9 ¦ 15 Mn 3.8 _ 3.0 _ l 19 Gd 8.0 2.1 7.1 ¦ 20 _Mn 3.9 3.0 .
¦ 21 Gd 5.3 2.0 5.8 _ ¦ 22 Mn 5.2 4.1 23 Gd 4 . 9 1 . 7 6 . 3 .
.. ~ ~ . . .... .. . ., .:
, ~ .
The solution was evaporated until 25-30 ml remained.
Subsequently ether (12Oml) was added, The precipitate formed was isolated by filtration and dried.
Yield: 93.9%
ExamDle 13 2.5,8,11,14-Pentaaza-5,8,11-tris(carboxymethyl)-3,15-dioxo-1,15-bis(pYrid-3-yl~pentadecane DTPA-bis(anhydride) 1.0 g (2.8 mmol) was gradually added . , , ................... . : ~
, .. ..
.
WO92/11232 2~9~712 ~f`~51/~'~,6~ 1 to a stirred solution of 3-aminomethylpyridine 0.61 g (5.6 mmol) in dried acetonitrile (40 ml) at ambient temperature. The solution was stirred for 84 hours~
The precipitate formed was isolated by filtration and dried.
Yield: 87.6%
ExamPle 14 2,5,8,11-Tetraaza-5~8-bis(carboxymethyl)-3,10-dioxo~
1.12- bis(pyrid-3-yl~dodecane EDTA-bis(anhydride) 1.0 g (3.9 mmol) was gradually added to a stirred solution of 3-aminomethylpyridine 0.84 g (7.8 mmol) in dried chloroform (85 ml) at ambient temperature. The precipitate formed was isolated b~
filtration and dried.
Yield: 97.8% ' Melting point: 212-216C
Example 15 2,5.8,11-Tetraaza-5,8-bis(carboxymethyl)-3.10-dioxo-1,12- bisrpyrid-2-yl)dodecane EDTA-bis(anhydride) 1.0 g (3.9 mmol) was gradually added to a stirred solution of 2-aminomethylpyridine 0.84 g (7.8 mmol) in dried chloroform (120 ml) at ambient temperature. The stirred solution was left for 16 hours at ambient temperature. The solution was evaporated until 25-30 ml remained. Subsequently ether (50 ml) was added. The precipitate formed was isolated by filteration and dried.
Yield: 98.4%
Melting point: 73-81C.
.
.... . ...
.~ , , . : . . :~ . .: . : : , , . :
:: , ' : .' ' .,, ,:. ,., . :.: .
WO92/11232 2 ~ 9 8 .~ ~ 2 PCT/EP9~ 4~ ~
Example 16 3,6 9 12-Tetraaza-2 13-bis(benzyloxycarbonyl)-6,9-bis(carboxymethyl)-4~11-dioxo-1~14-diPhenyltetradecane EDTA-bis(anhydride) (0.4 g, 1.56 mmol) was added in portions to a solution of H-Phe-OBzl-HCl (0.91 g, 3.12 mmol) and triethylamine (0.32 g, 3.12 mmol) in chloroform (50 ml). The reaction mixture was stirred at ambient temperature for 20 hours before the white precipitated product was collected by filtration and dried under vacuum at 50C.
Yield: 0.83 g (69%), Melting point: 174-178C
Elemental analysis:
calculated: C 65.78 H 6.05, N 7.30 found: C 65.53, H 6.15, N 7.14 1H NMR (DMSO): ~ 8.32 (d, J 8.06 Hz, 2H), 7.5-7.08 (m, 20H), 5.10 (s, 4H), 4.70-4.50 (m, 2H), 3.50-2.41 (m, 16H).
Example l?
3,6,9 r 12 15-Pentaaza-2 16-bis(benzyloxycarbonyl)-6,9.12-tris(carboxymethyl)-4,14-dioxo-1 17-diPhenylhe~tadecane DTPA-bis(anhydride) (0.56 g, 1.56 mmol) was added in portions to a solution of H-Phe-OBzl-HCl (0.91 g, 3.12 mmol) and triethylamine (0.32 g, 3.12 mmol) in chloroform (50 ml). The reaction mixture was refluxed under N2 for 24 hours before the white precipitated product was collected by filtration and dried under vacuum at 50~C.
Yield: 1.1 g (81%), Melting point: 120-126C
1H NMR (DMSO): ~ 8.45 (d, J 7.78 Hz, 2H), 7.50-7.05 (m, 20H), 5.10 (s, 4H), 4.70 4.50 (m, 2H), 3.70-2.60 (m, . ' :, .' ' , ' .,' -.
W092/11232 2~ 7~ PCT/~ 2~$
22H).
.
Example 18 3.6 9.12-Tetraaza-2.13_dicarboxY 6.9-bislcarbQxYmethy 4.11-dioxo-1,14-diPhenyltetradecane LioH tO.34 g, 14.3 mmol) was added to a suspension of EDTA-bis(benzylphenylalanyl)amide (1.1 g, 1.43 mmol) in a mixture of methanol/water (3:1, 44 ml). After 2 hours the TLC showed that the hydrolysis was completed.
Methanol was removed under reduced pressure and the reaction mixture acidified to pH 3.5 with 2N HCl. The product was collected by filtration and dried under '~
vacuum at 50C.
Yield: 0.89 g, Melting point: 115-120C
H NMR (DMSO): ~ 8.22 (d, J 7.4 Hz, 2H), 7.50-7.08 (mr 1 OH), 4.61-4.35 (m, 2H), 3.40-2.40 (m, 16H).
Example 19 3.6 9,12 15-Pentaaza-2 16-dicarboxy-6 9.12-tris(carboxymethvl)-4 14-dioxo-1 17-diphen~lheptadecane LioH (0.30 g, 12.7 mmol) was added to a suspension of DTPA-bis(benzylphenylalanyl)amide (1.1 g, 1.27 mmol) in a mixture of methanol/water (3:1, 44 ml). After 2 hours the TLC showed that the hydrolysis was completed. The solvent was removed under reduced pressure and the residue dried under vacuum at 50C to give l.Q4 g of crude product.
1H NMR (DMSO): ~ 8.49 (d, J 1.6 Hz, 2H), 7.40-7.00 (m, 1 OH), 4.43-4.20 (m, 2H), 3.61-2.55 (m, 22H).
: ::~ :. . . , ,: . ,, WO9-/llZ32 2 0 9 ~ 7 12 PC~/EP9~/~246~ l ExamPle 20 3 ! 6,9,12-Tetraaza-6,9-bis(carboxYmethYl)-4,11-dioxo-1,14-bis(pyrid-2-YlLtetradecane A solution of 2-(2-aminoethyl)pyridine (0.95 g, 7O8 mmol) and EDTA-bis(anhydride) (1.0 g, 3.9 mmol) in 85 ml .
chloroform was stirred for 4 days at ambient temperature. Most of the chloroform was evaporatedO
The rest (20-30 ml) was dissolved in 100 ml diethylether to crystallize. The solid product was collected and dried under reduced pressure to yield 88% product.
Melting point: 60-64OC
Elemental analysis:
Calculated: C 56.05 H 6.25 Found: C 55.88 H 6.25 lH NMR (200 MHz DMSO-d6) ~ ppm: 2.66 (s, 4H, t, 4H, J =
7.1 Hz), 3.20 (s, 4H), 3.33 (s, 4H), 3.4-4.6 (m, 4H), 7.1-7.3 (m, 4H), 7.6-7.8 (m, 2H), 8.10 (t, 2H, 5.7 Hz), 8.50 (d, 2H, J = 4.7 Hz).
Exam~le 21 3.6.9 12 15-Pentaaza-6 ~9 12-trisrcarboxYmethY1)-4.14-dioxo-1 17-bis(PYrid-2-vl)heptadecane 2-(2-Aminoethyl)pyridine (0.68 g, 5.6 mmol) and DTPA-bis(anhydride) (1.0 g, 2.8 mmol) were dissolved in 85 ml chloroform. The mixture was stirred for 22 hours at ambient temperature. The solid product was separated from the solution by filtration before being dried in vacuum to give 56% product.
Melting point: 110-118C
Elemental analysis:
Calculated: C 53.36 H 6.18 Found: C 57.58 H 6.46 1H NMR (200 MHz DMSO-d6) ~ ppm: 2.8-3.8 (m, 30H), 7.1-7.4 ' ;' '. ~ ~: , " ' ;
'., . ;'' . ' ;' ', : '. ', ':
`
W092/1123Z PC~/EI~
2 ~ 2 (m, 4H), 7.6-7.8 (m, 2H), 8.1-8.3 (m, 2H), 8.49 (d, 2H, 4.8 Hz).
ExamPle 22 3,6 9~12-Tetraaza-2 13-dicarboxv-6,9-bis~carboxvmet~yl~ ¦
4.11-dioxo-1 14-bis(indol-3-vl~tetradecane Triethylamine (On39 g, 3.9 mmol), tryptophanmethylester (HCl) and EDTA-bis(anhydride~ (0.5 g, 1.95 mmol) were dissolved in 70 ml chloroform. The suspension was stirred for 21 hours at ambient temperature. The solid product was collected by filtration and dried in vacuum to give 83~ yield.
Melting point: 84-91C
Elemental analysis: ~ -Calculated: C 53.30 H ~.46 Found: C 58.94 H 5.83 H NMR (200 MHz DMSO-d6) ~ ppm: 2.26 (3, 4H), 3.0-304 (m 14H), 3.60 (s, 6H), 4.5-4.7 (m, 2H), 6.95-7.15 (m, 4H)~
7.19 (d, 2H, J = 1.8 Hz), 7.37 (d, 2H, J = 7.5 Hz), 7052 (d, 2H, 7.7 Hz), 8.27 (d, 2H, J = 7.7 Hz).
Example 23 3 6 9~12-Pentaaza-2 16-dicarboxv-6 9~12-tris(carboxYmeth~1)-4 14-dioxo-1 17-bis(indol-3-yl)heptadecane Triethylamine (0.57 g, 5.6 mmol), tryptophanmethylester (HCl) (1.43 g, 5.6 mmol) and DTPA-bis(anhydride) (1.000 g, 2.8 mmol) were dissolved in 100 ml chloroform. The mixture was refluxed in a nitrogen atmosphere for 3 days. Most of the chloroform was removed ~20-30 ml left). 100 ml diethylether was added to the concentrated solution. The crystalline product was '; ` ; -. , i , : !
WO92/11232 PCT/EP9FI/~2468 2~7 ~ 2, collected by filtration, dissolved in basic aqueous solution and recrystallized with 0.5 M HCl.
The identity of the product as the title compound was verified by 1H and 13C NMR.
Example 24 3,6.9,12-Tetraaza-2,13-bis(methvloxYcarbonyll-6,9 bis(carboxymeth~l~4,11-dioxo-1,14-bis(indol-3-Yl)tetradecane Lithium hydroxide (14.4 mg, 0.61 mmol) was dissolved in a 4.5 ml mixture of MeOH/H2O(3:1). 3,6,9,12-Tetraaza~
2,13,-bis(methyloxycarbonyl)-6,9-bis(carboxymethyl)-4,11-dioxo-1,14-bis(indol-3-yl)tetradecane (60.0 mg, 8.7 x 102 mmol) was added and the solution was stirred for 8 hours. Methanol was removed, 2 ml water was added and the pH was adjusted to 3.5 (0.5 M HCl). The solid product was collected and dried in vacuo for 12 hoursO
The identity of the product as the title compound was verified by lH NMR.
Exam~le 25 3.6,9,12,15-Pentaaza-2 16-bis(methYloxYcarbonYl)-6.9.12-tris(carboxymethyl) 4,14-dioxo-1 17-bis(indol-3-vl)heptadecane Lithium hydroxide (0.32 g, 13.4 mmol) was dissolved in a mixture of MeOH/H2O(3:l). 3,6,9,12,15-Pentaaza-2,16,-bis(methyloxycarbonyl)-6,s,12-tris(carboxymethyl)-4,14-dioxo-1,17-bis(indol-3-yl)heptadecane (1.33 g, 1.67 mmol~ was added and the solution was stirred for 6 hours at ambient temperature. Methanol was evaporated and 10 ml water was added to the residual. The pH was adjusted to 3.5 with 0.5 M HCl. The solid product was collected , ', .: , . ; .: :-.: ~:.
WO92/11232 ~ 6~i 1 2 r by filtration and dried to give 18% product.
Melting point: 158-160C
Elemental analysis:
Calculated: C 55.86 H 5.80 Found: C 56.45 H 5.67 1H NMR (200 MHz, DMSO-d6) ~ ppm: 2.5-3.6 (m, 22H), 4 4~
4.7 (m, 2H), 6.9-7.2 (m, 4H), 7.22 (s, 2H), 7.36 (d, 2H, J = 7.5 Hz), 7.56 (d, 2H, J = 7.4 Hz), 8.27 (d, 2H, J =
8.1 Hz).
Example 26 General procedure for complexation w:ith Gadolinium (20 mM solution) GdCl3 (1 mmol) in 4 ml water was dropwise added to a solution of a chelant of formula I (where n is 1) (1 mmol) in 30 ml water, while the pH was kept at 5-6 by adding 1 N NaOH. After addition the mixture was stirred for 1/2 hour and diluted with water to 50 ml.
Exam~le 27 General ~rocedure for complexation with Man~anese (50 mM
solution) MnCl2 (1.25 mmol) in 3 ml water was dropwise added to a solution of a chelant of formula I (where n is 0) (1.25 mmol) in 15 ml water, while the pH was kept at 5-6 by adding lN NaOH. After addition the mixture was stirred for 1/2 hour and diluted with water to 25 ml.
:. , ~' ~' , :' wO g2/1l232 2 0 9 ~ 7 ~ ~ PCT/EP91/02468 r .
Example 28 Relaxivitv of Gd and Mn chelates in water and AutonormR
measured at 37'C, 20 MHz on an IBM PC/20 Series NMR
Analyzer (Minispec).
I _ . .' Water AutonormR
Chela~ing agent Metal l , (Example No.) _ rl (mM'' s'') r2 (mM'' s'') r1 (mM'~ s' ) ¦ :
1 Mn 3.3 2.8 2 Gd 3.4 5.8 _ 7.0 ¦ .
3 Gd 4.6 3.9 6.0 4 Gd 4.3 7.2 7.5 7 Mn 3.7 2.6 Mn 5.4 1.5 11 _ Mn 3.9 3.3 12 Gd 3.7 6.5 6.3 ~:
j 13 Gd 3.2 5.9 5.9 14 Mn 3.4 1 3.9 ¦ 15 Mn 3.8 _ 3.0 _ l 19 Gd 8.0 2.1 7.1 ¦ 20 _Mn 3.9 3.0 .
¦ 21 Gd 5.3 2.0 5.8 _ ¦ 22 Mn 5.2 4.1 23 Gd 4 . 9 1 . 7 6 . 3 .
.. ~ ~ . . .... .. . ., .:
, ~ .
Claims (15)
1. A compound of formula I
(I) (wherein n is 0 or 1;
one group R1 is a group NR11R14 where R11 is a hydroxyl or alkoxy group or a group -L-Cy or -O-L-Cy, and R14 is a hydrogen atom, an alkyl group or a group -L-Cy, and the other group R1 is a hydroxyl group or a group NR11R14; L
is a bond or a straight-chain or branched saturated or unsaturated alkylene group optionally interrupted by a carbocyclic or heterocyclic saturated or unsaturated group and optionally attached to the Cy group by a peptide or carbonyl link and optionally substituted by further Cy groups or by aminocarbonyl, acyl or acylamino groups; and Cy is a cyclic lipophilic group; with the provisos that in any NR11R14 group one of R11 and R14 comprises a L-Cy group and that where n is l at least one R1 group is other than phenylamine, benzylamine, or methoxybenzylamine) and metal chelates and salts thereof.
(I) (wherein n is 0 or 1;
one group R1 is a group NR11R14 where R11 is a hydroxyl or alkoxy group or a group -L-Cy or -O-L-Cy, and R14 is a hydrogen atom, an alkyl group or a group -L-Cy, and the other group R1 is a hydroxyl group or a group NR11R14; L
is a bond or a straight-chain or branched saturated or unsaturated alkylene group optionally interrupted by a carbocyclic or heterocyclic saturated or unsaturated group and optionally attached to the Cy group by a peptide or carbonyl link and optionally substituted by further Cy groups or by aminocarbonyl, acyl or acylamino groups; and Cy is a cyclic lipophilic group; with the provisos that in any NR11R14 group one of R11 and R14 comprises a L-Cy group and that where n is l at least one R1 group is other than phenylamine, benzylamine, or methoxybenzylamine) and metal chelates and salts thereof.
2. A compound as claimed in claim 1 containing at least one Cy group which is a carbocyclic or heterocyclic saturated or unsaturated group itself optionally carrying one or more fused carbocyclic or heterocyclic saturated or unsaturated rings and optionally substituted by halogen atoms, alkyl, alkylamino, dialkylamino, carbamoyl, N-alkylcarbamoyl, acetamido, N-alkylacetamido or carbocyclic or heterocyclic saturated or unsaturated groups.
3. A compound as claimed in either of claims 1 and 2 containing at least one Cy group selected from optionally substituted benzene, pyridine, pyrimidine, pyrazine, 1,3-oxazine, 1,4-oxazine, 1,3-thiazine, 1,4 thiazine, pyrrole, imidazole, 1,3-oxazole, 1,3-thiazole, furan, thiophene, piperidine, piperazine, morpholine;
perhydro-1,4-thiazine and pyrrolidine rings.
perhydro-1,4-thiazine and pyrrolidine rings.
4. A compound as claimed in any one of claims 1 to 3 containing at least one Cy group selected from groups of formula Ia to Ie (Ia) (Ib) (Ic) (Id) (Ie) (where R3 to R8 is each independently a bond or a hydrogen or halogen atom or an alkyl, alkylamino, dialkylamino, carbamoyl, N-alkylcarbamoyl, acetamido or N-alkylacetamido group or two adjacent groups from R3 to R8 together form a C2-5 alkylene or azaalkylene bridge, the point of attachment to L being a carbon of said bridge or one of said groups R3 to R8; X is nitrogen or CH and Y is CH or nitrogen; X' is CH2, NH, oxygen, sulphur or a bond; X" is nitrogen, oxygen or sulphur and Y" is CH or nitrogen; and R9 is a bond or hydrogen, alkyl or aralkyl).
5. A compound as claimed in any one of claims 1 to 4 containing at least one group LCy of formula -(CHR10)k-(CO)a-(NR10)b-(CO)c-R10 where k is 0-10; a, b and c are 0 or 1, the sum of a and c being 0 or 1; each R10 is a hydrogen atom, an alkyl group, an optionally esterified carboxyl group or a group Cy, at least one being a group Cy, and one or more CHR10 moieties may optionally be replaced by a 5-7 membered saturated homo or heterocyclic ring.
6. A compound as claimed in any one of claims 1 to 5 wherein at least one group R1 is a group NR11R14 wherein R11 is a group -L-Cy and R14 is a hydrogen atom or an alkyl group.
7. A compound as claimed in any one of claims 1 to 6 being a compound of formula II
(II) (where n is 0 or 1, R15 is hydrogen or methyl and R13 is a group selected from benzyl, 2-phenyl-ethyl, 1-phenyl-ethyl, pyrid-4-yl, pyrid-3-yl, pyrid-2-yl, 3-morpholino-propyl, N-benzyl-piperidin-4-yl and indanyl groups and iodinated such groups) or a metal chelate or salt thereof.
(II) (where n is 0 or 1, R15 is hydrogen or methyl and R13 is a group selected from benzyl, 2-phenyl-ethyl, 1-phenyl-ethyl, pyrid-4-yl, pyrid-3-yl, pyrid-2-yl, 3-morpholino-propyl, N-benzyl-piperidin-4-yl and indanyl groups and iodinated such groups) or a metal chelate or salt thereof.
8. A compound as claimed in any one of claims 1 to 7 being a metal chelate of a compound of formula I, said metal being a paramagnetic ion of an element of atomic number 21-29, 42, 44 or 57-71.
9. A compound as claimed in claim 8 being a chelate of Gd, Mn or Dy.
10. A therapeutic or diagnostic composition comprising a compound of formula I or metal chelate thereof as defined in any one of claims 1 to 9 or a physiologically tolerable salt thereof together with at least one pharmaceutical or veterinary carrier or excipient.
11. A process for the preparation of compound, as claimed in claim l said process comprising reacting EDTA
or DTPA or an activated or protected derivative thereof with an amine of formula III
HNR11'R14' (III) where R11' and R14' are groups R11 and R14 as defined in claim 1 or protected such groups, followed where desired by deprotection, metallation or salt formation.
or DTPA or an activated or protected derivative thereof with an amine of formula III
HNR11'R14' (III) where R11' and R14' are groups R11 and R14 as defined in claim 1 or protected such groups, followed where desired by deprotection, metallation or salt formation.
12. A method of generating enhanced images of the human or non-human animal body, which method comprises administering to said body a metal chelate of a compound of formula I as defined in claim l or a physiologically tolerable salt thereof and generating an X-ray, MR-diagnostics, ultrasound or scintigraphic image of at least a part thereof.
13. A method of radiotherapy practised on the human or non-human animal body, which method comprises administering to said body a chelate of a radioactive metal species with a chelating agent of formula I as defined in claim 1 or a physiologically tolerable salt thereof.
14. A method of heavy metal detoxification practised on the human or non-human animal body, which method comprises administering to said body a chelating agent which is a salt of a compound of formula I as defined in claim 1 with a physiologically acceptable counterion.
15. The use of compounds as claimed in claim 1 for the manufacture of diagnostic or therapeutic agents for use in methods of image generation, detoxification or radiotherapy practised on the human or non-human animal body.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9027922.5 | 1990-12-21 | ||
| GB909027922A GB9027922D0 (en) | 1990-12-21 | 1990-12-21 | Compounds |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2098712A1 true CA2098712A1 (en) | 1992-06-22 |
Family
ID=10687517
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002098712A Abandoned CA2098712A1 (en) | 1990-12-21 | 1991-12-20 | Chelating agents |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0563145A1 (en) |
| JP (1) | JPH06504273A (en) |
| CA (1) | CA2098712A1 (en) |
| GB (1) | GB9027922D0 (en) |
| WO (1) | WO1992011232A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0603403A1 (en) † | 1992-07-03 | 1994-06-29 | The Green Cross Corporation | Novel chelating agent, complex compound composed of said agent and metallic atom, and diagnostic agent containing said compound |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5562894A (en) * | 1991-08-09 | 1996-10-08 | Regents Of The University Of California | Amino-acyl-type and catecholamine-type contrast agents for MRI |
| EP0598837A4 (en) * | 1991-08-09 | 1994-07-13 | Univ California | Amino acid, ester and/or catechol contrast agents for mri. |
| AU671465B2 (en) * | 1992-07-31 | 1996-08-29 | Australian Nuclear Science & Technology Organisation | Metal complexes of hydroxyaryl containing aminocarboxylic acid chelating agents |
| US5807535A (en) * | 1992-07-31 | 1998-09-15 | Australian Nuclear Science & Technology Organisation | Metal complexes of hydroxyaryl containing aminocarboxylic acid chelating agents |
| ES2146217T3 (en) * | 1992-07-31 | 2000-08-01 | Australian Nuclear Science Tec | CHELATING AGENTS OF AMINO CARBOXYL ACIDS WITH HYDROXYARIL. |
| DE19507820A1 (en) * | 1995-02-21 | 1996-08-22 | Schering Ag | Novel substituted DTPA derivatives, their metal complexes, pharmaceutical compositions containing these complexes, their use in diagnostics, and methods for producing the complexes and compositions |
| EP1343758A1 (en) | 2000-11-08 | 2003-09-17 | K.U. Leuven Research & Development | Substituted bis-indole derivatives useful as contrast agents, pharmaceutical compositions containing them and intermediates for producing them |
| DE102020214114A1 (en) | 2020-11-10 | 2022-05-12 | Henkel Ag & Co. Kgaa | Metal complexes and dishwashing detergents containing them |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE786946A (en) * | 1971-07-29 | 1973-01-29 | Ciba Geigy | CHELATES TO COMBAT SYMPTOMS OF METAL DEFICIENCY IN BIOLOGICAL SYSTEMS |
| CH569405A5 (en) * | 1972-07-11 | 1975-11-28 | Ciba Geigy Ag | Combatting metal deficiency in biological systems - with metal chelates of ethylene diamine tetraacetic acid diamide derivs |
| DE2511891A1 (en) * | 1975-03-19 | 1976-10-07 | Gruenenthal Chemie | Anti-thrombotic dioxo-piperazine derivs - prepd. e.g. by cyclising N,N,N',N'-1,2-alkylene-diamine-tetraacetic acids with amines |
| DE3324235A1 (en) * | 1983-07-01 | 1985-01-10 | Schering AG, 1000 Berlin und 4709 Bergkamen | NEW COMPLEX ILLUMINATORS, COMPLEX AND COMPLEX SALTS |
| US4687659A (en) * | 1984-11-13 | 1987-08-18 | Salutar, Inc. | Diamide-DTPA-paramagnetic contrast agents for MR imaging |
| DE3927444A1 (en) * | 1989-08-16 | 1991-02-28 | Schering Ag | USE OF AMID COMPLEX COMPOUNDS |
-
1990
- 1990-12-21 GB GB909027922A patent/GB9027922D0/en active Pending
-
1991
- 1991-12-20 WO PCT/EP1991/002468 patent/WO1992011232A1/en not_active Application Discontinuation
- 1991-12-20 JP JP4501395A patent/JPH06504273A/en active Pending
- 1991-12-20 EP EP92901385A patent/EP0563145A1/en not_active Withdrawn
- 1991-12-20 CA CA002098712A patent/CA2098712A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0603403A1 (en) † | 1992-07-03 | 1994-06-29 | The Green Cross Corporation | Novel chelating agent, complex compound composed of said agent and metallic atom, and diagnostic agent containing said compound |
| EP0603403B2 (en) † | 1992-07-03 | 2001-06-27 | Welfide Corporation | Novel chelating agent, complex compound composed of said agent and metallic atom, and diagnostic agent containing said compound |
Also Published As
| Publication number | Publication date |
|---|---|
| WO1992011232A1 (en) | 1992-07-09 |
| JPH06504273A (en) | 1994-05-19 |
| EP0563145A1 (en) | 1993-10-06 |
| GB9027922D0 (en) | 1991-02-13 |
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| FZDE | Dead |