NL193318C - N- [N'-substituted carbamoylmethyl] iminodiacetic acids and preparations containing these compounds. - Google Patents

Description

1 193318 N- (N'-substituted carbamoylmethyl) iminodiacetic acids and preparations containing these compounds

The present invention relates to N- (N'-substituted carbamoylmethyl) iminodiacetic acids and their water-soluble, pharmaceutically acceptable salts thereof, which form complexes with technetium, a large percentage of which, after injection into a mammal, enter the bile and whose renal excretion is low.

Such compounds are known from DE-A-2.723.605. Described herein are complexes of the 99m Tc ion with a dicarboxylic acid of formula 1 of the formula sheet, where n = 0, R 3 represents a hydrogen atom and at least two of the substituents R 1, R 2 and R 4 represent an alkyl group of 1 to 4 carbon atoms, the third substituent represents a hydrogen atom or an alkyl group of 1 to 4 carbon atoms, and the three substituents contain at least three carbon atoms in total. These complexes are used for scintillographic imaging of the hepatic biliary system, in particular of the dynamic processes taking place there, and in particular transport through the hepatic biliary system. Compared to the known 1311-labeled preparations such as iodine-131 Bengal pink, these complexes have the advantage that 99mTc has a half-life of 6 hours instead of 8.05 day and emits 13% non-penetrating, diagnostically useless quanta instead of 42%, which significantly reduces the patient's radiation exposure, especially when there is no renal excretion, which is precisely what is desired for liver function diagnosis.

New N-substituted aminodiacetic acids have now been found to form complexes with technetium, have good specificity (ie when injected into a mammal, a large percentage of the complex enters the bile via the liver) and the radioactivity rapidly from the liver to transport the bile, and the excretion of which is small through the kidney.

The invention provides compounds as described in the preamble, characterized in that they comply with formula 1 of the formula sheet, wherein R 1 and R 4 independently represent a hydrogen atom or a methyl or ethyl group and one of the substituents R 2 and R 3 an alkyl group of 1 to 4 carbon atoms and the other of the substituents R2 and R3 represents a bromine or iodine atom, and n is 0, 1 or 2.

The compounds of the invention are rapidly absorbed by the liver cells, rapidly transported through the liver, and rapidly excreted in the biliary system, while excreted little by the kidney. Due to the rapid increase and decrease of the concentration in the liver, the time required for examination is short, which is important for patients who cannot be immobilized for a long time. In addition, the number of patients treated in a given period of time can be increased and the use of the equipment is optimal. A rapid decrease in the liver also means an increase in the ratio of the radioactivity in the bile to that in the liver, making the bile ducts in the liver visible and thus the quality of the image and that of the subsequent diagnosis improved.

Regarding the use of 99mTc and compounds that form complexes therewith, reference can still be made to the following literature.

The development of Tc-99m penicillamine by Tubis et al. (Radiopharmaceuticals, Ed. Subramanian et al., 40 The Society of Nuclear Medicine, Inc., New York, 1975, biz. 55-62) was an important step in overcoming the limitations of the iodine-131 mark and to stimulate research interest in liver bile agents marked with technetium-99m.

Among the most useful technetium-99m labeled agents currently developed are the N-substituted iminodiacetic acids (hepatoiminodiacetic acids; HIDAs). U.S. Patent No. 4,017,596 discloses, inter alia, the use of a chelate of technetium-99m and a substituted iminodiacetic acid for external organ imaging. U.S. Patent 3,725,295 discloses the marking of diethylene triamine pentaacetic acid (DTPA) with technetium-99m.

The various HIDA derivatives disclosed in the literature can be represented by formula 1a. The derivatives discussed include the 2,6-dimethyl derivative (U.S. Patent 4,017,596), the 2,6-diethyl, 2,6-diisopropy, 2-butoxy, 4-butoxy, 4-butyl , 4-isopropyl, 4-ethoxy and 4-iodo derivative (Wistow et al., Radiology, 128: 793-794, 1978; the 2,3-dimethyl, 2,4-dimethyl, 2,5-dimethyl, 3,4-dimethyl and 3,5-dimethyl derivative (Van Wyk et al., Eur. J. Nucl. Med., 4: 445-448, (1979)) and 2,4,6-tri-substituted derivatives, wherein at least two of the substituents are an alkyl group with 1-4 carbon-55 atoms, the third substituent is a hydrogen atom or an alkyl group with 1-4 carbon atoms and the substituents together contain at least 3 carbon atoms (Belgian patent 855,107) and the 2,6 -dimethyi, 2,6-diethyl-, 2,6-diisopropyi, 4-methyl-, 4-ethyl-, 4-n-butyl, 4-n-pentyl, 4-t-butyl, 4 -phenyl-, 193318 2 4-methoxy-, 3,5-dimethyl-, 2,4,6-trimethyl-, 2,4,5-trimethyl-, 4-fluoro-, 2,4-difluoro-, 2, 5-difluoro and 2,3,4,5,6-pentafluoro derivatives (Molter et al. 3rd Int. Symp. Radiopharm. Chem., St. Louis. Mo., June 1980). Fields et al. Journal of Labeled Compounds and Radiopharmaceuticals, XV: 387-399 (1978) disclose N- (2-phenethylcarbamoylmethyl) iminodiacetic acid.

5 Van Wyk et al., Eur. J. Nucl. Med., 4: 445-448, 1979 have shown in their work with dimethyl-HIDA derivatives that steric effects of substituents are important for bile uptake. Chiotellis et al., Int.

J. Nycl. Med. Biol., 7: 1-7, 1980, working with 4-butyl-HIDA compounds, have shown that the molecular size of substituents is important for biliary uptake.

EP-A-0 019 790 describes technetium complexes with N-pentafluorophenylcarbamoylmethyl) iminodiacetic acid and N- (4-n-pentylphenylcarbamoylmethyl) iminodiacetic acid which give low renal excretion. EP-A-0.012.967 describes technetium complexes with N- (2,4,5-trimethylphenylcarbamoylmethyl) iminodiacetic acid which give low renal excretion and fast hepatic passage. GB-A-2,018,762 discloses N- (2,4-dialkylphenylcarbamoylmethyl) aminodiacetic acid chelates of radioactive metals including technetium-99m with a longer radiochemical life and improved biological and scintillographic results. This literature does not describe compounds containing a phenyl group with a bromine or iodine substituent.

Compounds of formula 1 of the invention and salts thereof can be labeled with technetium-99m and then administered intravenously to a patient for the purpose of imaging the bile system and liver. The radiolabelling of the compound of formula 1 and its salts can be done by well known methods. In a preferred procedure, 20 technetium-99m in the form of an aqueous sodium pertechnetate solution (Na99mTcO 4) is combined with a reducing agent and a compound of the formula 1 or salt thereof. Although the order of mixing of the three components described above is not critical, it is most preferred to first combine the reducing agent with a compound of the formula 1 of the invention. This formulation (a non-radioactive formulation) can then be supplied to radio chemists, technicians, radiopharmacists or doctors for marking with technetium-99m just before use.

Stannous ion is the preferred reducing agent. Examples of stannous reducing agents are stannous chloride and stannous fluoride. Technetium-99m in the form of an aqueous solution of sodium pertechnetate is readily available from commercially available molybdenum-99 / technetium-99m generators, which are conventionally eluted with brine.

The compounds of the formula I according to the invention can be prepared starting from nitrilotriacetic acid, acetic anhydride and an amine derivative of the formula 2. Nitrilotriacetic acid and acetic anhydride are first reacted to form nitrilotriacetic anhydride, which is then reacted with an amine of the Formula 2 to obtain the corresponding compound of Formula 1. The reactions proceed most easily when the reagents are present in stoichiometric amounts.

The compounds of formula 1 can be converted into pharmaceutically acceptable water-soluble salts using art-recognized procedures. Preferred salts are alkali metal salts and alkaline earth metal salts.

The compounds of formula 1 (and its salts) can be prepared for complexing with technetium-99m using art-recognized procedures. For example, one can prepare a "wet 40 set" by first dissolving a compound of formula 1 (or its salt) in base (e.g. sodium hydroxide) to obtain a solution having a pH of about 6-7. an acidic reducing agent solution (for example stannous fluoride) in hydrochloric acid is added Water can be added to give the desired volume Technetium-99m, preferably an aqueous solution of sodium pertechnetate, can be added to this solution, lyophilized sets can be prepared under using the procedure described above, but now the solution is lyophilized before the addition of technetium-99m The lyophilized material can be stored in an inert atmosphere.

Preferred compounds of the invention are those of formula 1, wherein n = 0. Particularly preferred are those compounds of formula 3 or a pharmaceutically acceptable water-soluble salt 50 thereof, wherein one of the substituents R'2 and R'3 is a is a methyl or ethyl group and the other is a bromine or iodine atom.

The following examples are specific embodiments of the invention.

Example I

55 2.2 '- [[2 - [(3-Bromo-2,4,6-trimethylphenyl) amino] -2-oxoethyl] imino] bisacetic acid.

A) 3-Bromo-2,4,6-trimethylaniline.

80 ml of concentrated hydrochloric acid were cooled to 5 ° C in an ice-water bath. 13.5 g of 2,4,6-3,333,318 trimethylaniline was added over 20 minutes with vigorous stirring, keeping the temperature below 15 ° C. The thick slurry was cooled to 3 ° C and 16.8 g of bromine in 80 ml of concentrated hydrochloric acid was added over 25 minutes. The slurry was heated in a water bath for 1 hour and then cooled in an ice bath for 1 hour. The reaction mixture was then filtered and the salt was washed with three 50 ml portions of cold distilled water. After drying, the crude product was dissolved in 600 ml of distilled water, treated with 3.0 g of Darco (activated carbon) and filtered on a Hyflo (kieselguhr) bed to obtain a solution. Neutralization of the filtrate with concentrated ammonium hydroxide gave a milky solution, from which the product solidified on cooling to 10 ° C. After cooling for about 16 hours, the brown product was filtered off, washed with cold distilled water and dried in vacuo for about 16 hours to give 12.0 g of the title compound, mp 34.0-35.0 ° C.

B) 2,2 '- [[2 - [(3-Bromo-2,4,6-trimethylphenyl) amino] -2-oxoethyl] imino] bisacetic acid.

A suspension of 9.56 g nitrilo triacetic acid in pyridine (dried over molecular sieves) was prepared with exclusion of moisture (CaSO 4 drying tube) and heated to 50 ° C. 5.11 g of acetic anhydride were added dropwise. The reaction mixture quickly became clear and was heated to 100 ° C. After maintaining the temperature for 40 minutes, the reaction mixture was cooled to 55 ° C and a solution of 10.7 g of 3-bromo, 2,4,6-trimethylaniline in 25 ml of dry pyridine was slowly added. The reaction mixture was heated to 100 ° C and after 1.5 hours at this temperature, the solution was cooled in an ice bath. The reaction mixture was evaporated on a rotary evaporator to a semi-solid, which was dissolved in 125 ml of 10% sodium hydroxide w / v. The basic layer was then extracted twice with 100 ml of methylene chloride each time. 100 ml of distilled water were added to the basic layer, which was then brought to a pH of 3 with concentrated hydrochloric acid to obtain a precipitate. After cooling for about 16 hours, the crude product was filtered off, washed with cold distilled water and dried in vacuo at 40 ° C. The crude product was dissolved in 100 ml of 60% aqueous ethanol, treated with 3.0 g of Darco (activated carbon) and filtered hot through a Hyflo (kieselguhr) bed to obtain a solution.

Crystals precipitated and were filtered off, washed with 25 ml 50% aqueous ethanol three times each and dried in vacuo at 40 ° C. The reaction gave 9.1 g of the title compound, m.p. 198-200 ° C with decomposition.

Example II

2.2 '- [[2 - [(3-Bromo-2,6-diethyl-4-methylphenyl) amino] -2-oxoethyl] imino] bisacetic acid.

A) 3-Bromo-2,6-diethyl-4-methylaniline.

10 ml of concentrated hydrochloric acid was cooled to 5 ° C in an ice-water bath and 1.63 g of 2,6-diethyl-4-methylaniline was added dropwise to obtain a slurry. 1.59 g of bromine with 10 ml of concentrated hydrochloric acid were added dropwise over 30 minutes. The reaction mixture was stirred for 3.75 hours and 25 ml of distilled water was added. After cooling for 1.0 hour, the reaction mixture was filtered and washed twice with 25 ml of cold distilled water. After drying in vacuo for about 16 hours, the crude solid (2.3 g) was dissolved in 100 ml of 10% NaOH and extracted with 150 ml and then with 100 ml of methylene chloride. After drying over sodium sulfate, the methylene chloride solution was evaporated on a rotary evaporator to 1.9 g of crude product.

40 B) 2,2 '- [[2 - [(3-Bromo-2,6-diethyl-4-methylphenyl) amino] -2-oxoethyl] imino] bisacetic acid.

A slurry of 1.34 g of nitrilotriacetic acid in 15 ml of dry pyridine (dried over molecular sieves) was prepared and heated to 46 ° C. 0.72 g of acetic anhydride (rinsing with 1 ml of pyridine) was added and the solution was heated to 100 ° C. After heating for 0.5 hours, the solution was allowed to cool to 46 ° C and slowly added a solution of 1.7 g of crude 3-Bromo-2,6-diethyl-4-methylaniline in 6 ml of 45 pyridine. The solution was heated to 100 ° C for 2 hours, cooled and evaporated on a rotary evaporator to a paste-like product. The product was dissolved in 25 ml of 10% sodium hydroxide and the resulting solution was extracted twice with 25 ml portions of methylene chloride. The aqueous solution was diluted with 50 ml of distilled water, neutralized with concentrated salt salt to a pH of 3.0 and cooled for about 16 hours. Filtration gave a solid which, upon drying, gave 1.4 g of crude product in vacuo at 60 ° C for 3 hours. Recrystallization from 25 ml of 50% ethanol gave 1.04 g of needles mp 194.5-195.5 ° C.

Example III

2,2 '- [[2 - [(3-iodo-4-methylphenyl) amino] -2-oxoethyl] imino] bisacetic acid.

55 A slurry of 4.78 g of nitrilotriacetic acid in 40 ml of dry pyridine (dried over molecular sieves) was heated to 60 ° C. 2.55 g of acetic anhydride was slowly added and the solution was heated to 100 ° C. After heating for 0.5 hours, the solution was cooled to 40 ° C and a solution of 5.8 g of 3-iodo-4-methylaniline in 20 ml of dry pyridine was added over 25 minutes. The solution was heated to 100 ° C for 1.0 hour. The reaction mixture was cooled and rotary evaporated to a residue, then dissolved in 65 ml of 10% sodium hydroxide. This solution was extracted twice with 50 ml portions of methylene chloride, diluted with 100 ml of distilled water and neutralized to pH 3.2 with concentrated hydrochloric acid. The crude product was cooled for about 16 hours, filtered, washed twice with 50 ml portions of distilled water, and dried in vacuo at 40 ° C. The crude product (8.0 g) was recrystallized after treatment with Darco (activated carbon) to obtain 5.7 g of product mp 213.5-215.0 ° C with decomposition.

Example IV

2,2 '- [[2 - [(4-Bromo-3-methylphenyl) amino] -2-oxoethyl] imino] bis bis acetic acid.

A slurry of 9.56 g of nitrilotriacetic acid in 80 ml of dry pyridine (dried over molecular sieves) was heated to 55 ° C. 7.66 g of acetic anhydride were added and the solution was heated to 100 ° C. After heating for 0.5 hours, the solution was cooled to 55 ° C and a 9.30 g of 4-bromo-3-15 methylaniline was added with a 5 ml pyridine rinse. The solution was heated to 100 ° C for 1.0 hour. The reaction mixture was cooled and rotary evaporated to a pasty solid, which was dissolved in 120 ml of aqueous ammonium hydroxide (30 ml of concentrated ammonium hydroxide / 90 ml of distilled water). The clear brown solution was extracted with two 100 ml portions of methylene chloride and neutralized to pH 3 with 35 ml of concentrated hydrochloric acid. The white solid was filtered off, washed three times with 25 ml portions of cold distilled water, and dried in vacuo at 60 ° C for 2.75 hours. The crude product (12.9 g) was recrystallized from 360 ml of 50% ethanol to give 9.85 g of product mp 206.5-209.0 ° C.

Example V

2.2 '- [[2 - [(3-Bromo-4-methylphenyl) amino] -2-oxoethyl] imino] bis bis acetic acid.

A slurry of 4.78 g of nitrilotriacetic acid was prepared in 40 ml of dry pyridine (dried over molecular sieves) and heated to 50 ° C. 2.55 g of acetic anhydride was slowly added and the solution was heated to 100 ° C. After heating for 0.5 hours, the solution was cooled to 42 ° C and 4.81 g of 3-Bromo-4-methylaniline in 5 ml of pyridine was slowly added. The solution was heated to 100 ° C. After heating for 2.0 hours, the reaction mixture was cooled and rotary evaporated. This material was dissolved in 75 ml of 10% sodium hydroxide and extracted twice with 50 ml portions of methylene chloride. The aqueous raffinate was diluted with 100 ml of distilled water, neutralized to a pH of 3.2 with concentrated hydrochloric acid and cooled overnight for about 16 hours. The reaction mixture was filtered and washed with cold distilled water. After drying in vacuo at 60 ° C for 3 hours, 7.14 g of crude product mp 206.0-208.0 ° C were obtained. Recrystallization from 150 ml of 75% ethanol gave 6.4 g of solid, mp 209.0-210.0 ° C.

Example VI

Recipes for complex formation with technetium-99m 40 The following table gives examples of recipes of compounds of formula 1 with stannous fluoride as reducing agent. The recipes were prepared by dissolving the ligand in 0.46 M sodium hydroxide to give a solution with a final pH of about 6-7.5. 0.01 ml of a 70 mg / ml solution of stannous chloride in 6 M hydrochloric acid was added to this and the volume was adjusted to 5 ml of water for injection. The recipes in the following table have a preferred ligand: tin molar ratio of 150: 1.

45

TABLE

Concentration (mg / ml)

Ligande Ligande Stannous fluoride pH

50 - 2.2 '- [[2 - [(3-Bromo-2,4,6- 48,6 0,14 6,76 trimethylphenyl) amino] -2-oxoethyl iminoj bis acetic acid 2,2' - {[2 - [(3 - [(3-Bromo-2,6-diethyl-4- 51.9 0.14 5.99 55 methylphenyl) amino] -2-oxoethyl] imino] bis bis acetic acid

Claims (2)

5 193318 TABLE (continued) Concentration (mg / ml) Ligand Ligand Stannofluoride pH 5 ------------- 2.2 '- [[2 - [(3-Iodo-4-methylphenyl) amino ] -2- 50.4 0.14 7.55 oxoethyl-iminojbisacetic acid 2,2 '- [[2 - [(4-Bromo-3-methylphenyl) amino] - 44.6 0.14 5.96 2-oxoethyl ] -imino] bisacetic acid 10 2,2 '- [[2 - [(3-Bromo-4-methylphenyl) amino] - 44.9 0.14 7.39 2-oxoethyl] -imino] bisacetic acid 15 Conclusions 1. N- (N'-substituted carbamoylmethyl) iminodiacetic acids and their water-soluble, pharmaceutically acceptable salts thereof, which form complexes with technetium, a large percentage of which, after injection into a mammal, enters the bile and is secreted by the liver. is not small, characterized in that they comply with formula 1 of the formula sheet, wherein R 1 and R 4 independently represent a hydrogen atom or a methyl or ethyl group and one of the substituents R 2 and R 3 represents an alkyl group having 1 to 4 represents carbon atoms and the other of the substituents R2 and R3 represents a bromine or iodine atom, and n is 0, 1 or 2. A composition containing a compound according to claim 1 and a stannous reducing agent. Hereby 1 sheet drawing