FR2497197A1 - N-SUBSTITUTED IMINODIACETIC ACIDS USEFUL FOR EXTERNAL VISUALIZATION OF THE HEPATOCIAL SYSTEM - Google Patents

Abstract

NEW COMPOUNDS OF FORMULA: (CF DRAWING IN BOPI) POSSIBLY IN THE FORM OF WATER-SOLUBLE AND PHARMACEUTICALLY ACCEPTABLE SALTS, IN WHICH R AND R ARE EACH, INDEPENDENTLY, A HYDROGEN ATOM OR A METHYL OR ETHYL RADICAL; ONE OF R AND R IS A RADICAL ALKYL OF 1 TO 4 CARBON ATOMS AND THE OTHER IS A BROMINE OR IODINE ATOM; AND N IS 0, 1 OR 2. THESE COMPOUNDS, WHEN FORMED AS COMPLEXES WITH TECHNETIUM-99M IN THE PRESENCE OF A REDUCING AGENT, PROVIDE COMPOSITIONS THAT ARE USEABLE FOR EXTERNAL VIEWING OF THE HEPATOBILIARY SYSTEM.

Description

N-substituted iminodiacetic acids, usable for visualization

  The present invention relates to compounds of formula I ## STR2 ##

R 4 CH -C-OH

03

  as well as their water-soluble and pharmaceutically acceptable salts, wherein R1 and R4 are each, independently, a hydrogen atom or a methyl or ethyl radical; one of R 2 and R 3 is an alkyl radical of 1 to 4 carbon atoms and the other is a bromine or iodine atom and n is 0, 1 or 2. The present invention also relates to compositions comprising the compounds of formula I (and their salts) and a reducing agent, which can be complexed with technetium-99m. In Formula I, and throughout the specification, the

  symbols have the previous definitions.

  The technetium-99m complexes and a compound of formula I can be used for external visualization of the hepatobiliary system. These complexes have good specificity (i.e., when injected into a mammal, a large percentage of the complex passes into the bile through the liver) and exhibit rapid liver transport. to bile, allowing good measures

Bile.

  With the exception of the brain, the liver is the organ most often examined by nuclear medicine techniques. Most of these studies involve the intravenous administration of labeled particles such as Tc-99m sulfur colloid which are actually picked up by Kupffer cells. The diagnostic information thus obtained is useful for studying the

  Liver morphology and function of Kupffer cells.

  The optimal agent for these studies would have rapid and exclusive uptake into healthy Kupffer cells and would be

biodegradable and nontoxic.

  Radio studies are also used.

  nuclides to measure the functions of hepatocytes and the power of the common bile duct (including gallbladder function). The optimal agent for these studies would be rapid and exclusive uptake by hepatocytes, rapid intrahepatic transit, and immediate excretion into the biliary system. High specificity is required to obtain maximum diagnostic information while limiting the dose of radiation inflicted on the patient. The time required to obtain the maximum concentration in the liver (tmax) and the time required to reduce the concentration in the liver to 50% of the concentration tmax (t50) must both be short to reduce the time required to a study. This is important for patients who can not be immobilized for a long time. Shorter study durations increase the number of patients that can be examined in a given period of time, making the visualization equipment as cost-effective as possible. A short t50 also means an increase in the level of radioactivity in the bile compared with the level of radioactivity of the liver, thus separating the intrahepatic ducts from the liver and thus improving the

  picture quality and resulting diagnosis.

  Until recently, most studies of bile function in nuclear medicine

  were performed with I-131 Bengal rose or bromo-

  sulfophthalein I-131. Although the I-131 pink bengal is usually the standard for comparing liver function agents, its photon energy is not optimal for scintillation camera visualization, and the patient's exposure to beta radiation not used for diagnosis limits the dose that can be administered safely. The fineness of the image, and therefore

  diagnostic information, is limited.

  The development of penicillamine Tc-99m by Tubis et al (Radiopharmaceuticals, Subramanian et al., Eds., The Society of Nuclear Medicine, Inc., New York, 1975, pages -62) in 1974 was an important step towards overcome the limitations of iodine-131 labeling and to stimulate research interest in technetium-99m-labeled hepatobiliary agents. Among the most useful technetium-99m-labeled agents that have been

  to date, we find the iminodiacetic acids N-

  substituted (hepato-iminodiacetic acid or HIDA). Loberg et al., In U.S. Patent No. 4,017,596, disclose, inter alia, the use of technetium-99m chelate and substituted iminodiacetic acid for the external visualization of organs. Eckelman et al., U.S. Patent No. 3,725,295, disclose the labeling of diethylenetriaminepentaacetic acid.

(DTPA) with technetium-99m.

  The various HIDA derivatives which have been disclosed in the literature can be represented by the formula: ## STR1 ## The analogs in question include the 2,6-dimethyl derivative

  (Loberg et al., U.S. Patent No. 4,017,596); derivatives 2,6-

  diethyl, 2,6-diisopropyl, 2-butoxylated, 4-butoxylated, 4-butylated, 4isopropylated, 4-ethoxylated and 4-iodinated (Wistow et al., Radiology,

  128: 793-794, 1978); 2,3-dimethyl derivatives, 2,4-

  dimethyl, 2,5-dimethyl, 3,4-dimethyl and 3,5-dimethyl (Van Wyk et al., Eur J Nucl Med, 4: 445-448, 1979); and 2,4,6-trisubstituted derivatives of which at least two of the substituents are alkyl radicals of 1 to 4 carbon atoms, the third being a hydrogen atom or an alkyl radical of 1 to 4 carbon atoms, and the substituents containing together at least three carbon atoms (patent

  Belgian N 855.107); and 2,6-dimethyl derivatives, 2,6-

  diethyl, 2,6-diisopropyl, 4-methyl, 4-ethyl, 4-isopropyl, 4-n-butyl, 4-n-pentyl, 4-t-butyl, 4-phenyl, 4-methoxyl,

2497 1 97

  3,5-dimethyl, 2,4,6-trimethyl, 2,4,5-trimethyl, 4-fluorinated, 2,4-difluorinated, 2,5-difluorinated and 2,3,4,5,6-pentafluorinated ( Molten 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.

  Van Wyk et al., Eur. J. Nucl. Med., 4: 445-448, 1979, in their work on dimethyl derivatives of HIDA, have shown that the steric effects of substituents are important for bile absorption. Chiotellis et al., Int. J. Nucl. Med. Biol., 7: 1-7, 1980, in their work on 4-butyl compounds of HIDA, showed that the molecular size of the substituents was important.

for bile absorption.

  The compounds of formula I according to the present invention, as well as their salts, can be labeled with technetium-99m and then administered intravenously to a patient to provide an image of the hepatobiliary system. The radiolabelling of the compounds of formula I and their salts can be by methods well known in the art. According to a preferred method, technetium-99m is combined in the form of an aqueous solution of sodium pertechnetate (Na99mTcO4) with a reducing agent and a compound of formula I or a salt thereof.

  compound. The order of the mixture of the three components described above

  above is not crucial, but it is clearly preferable that the reducing agent is first combined with a compound of formula I according to the invention. This composition (no

  radioactive) can then be delivered to radio-

  chemists, technicians, radiopharmacists, doctors, etc., 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 can easily be obtained from commercially available molybdenum-99 and / or technetium-99m generators.

  which are conventionally eluted with saline.

  The compounds of formula I according to the invention can be prepared using as starting materials nitrilotriacetic acid, acetic anhydride, and an amine derivative having the formula R1 II R2 \ (CH2) n NH2

R 4

  Nitrilotriacetic acid is first reacted and

  acetic anhydride to obtain nitrilotri-

  acetic acid which is then reacted with an amine of formula II to obtain the corresponding compound of formula I. The reactions are quite easy if the products

  reactants are present in stoichiometric proportions.

  The compounds of formula I can be converted into water-soluble and pharmaceutically acceptable salts using methods known in the art. The preferred salts are the metal salts

  alkaline and alkaline earth metal salts.

  The compounds of formula I (and their salts) can be prepared for complex formation with technetium-99m using methods known in the art. For example, a "wet kit" can be prepared by first dissolving a compound of formula I (or a salt thereof) in a base (eg sodium hydroxide) to obtain a solution of pH 6 to about 7. . To this solution is added an acid solution of reducing agent (stannous fluoride for example) in hydrochloric acid. You can add water to get the

  desired volume. To this solution we can add technetium-

  99m, preferably in the form of an aqueous solution of sodium pertechnetate. Freeze-dried kits can be prepared using the method described above, except that prior to adding technetium-99m the solution is lyophilized. The lyophilized substance can be stored in

an inert atmosphere.

  The preferred compounds according to the invention are the compounds of formula I in which n is equal to 0. The compounds of formula:

C 'O

RU <H3 XCH -C-OH

H 2 He

C3 0

  optionally in the form of water-soluble and pharmaceutically acceptable salts, wherein one of R 'and R' is a methyl or ethyl radical and the other is

R2-3_ C.CO

a bromine or iodine atom.

  The following examples are forms

  specific embodiments of the invention.

EXAMPLE 1

  2,2 '- [[2 - [(3-bromo-2,4,6-trimethylphenyl) amino] -2- acid

  oxoethyllimino] bisacetic acid A) 3-Bromo-2,4,6-trimethylaniline 5 ml of concentrated hydrochloric acid are cooled to 5 ° C. in an ice-water bath. 13.5 g of 2,4,6-trimethylaniline are added over 20 minutes while stirring vigorously while maintaining the temperature below 15 ° C. The thick slurry obtained is cooled to 30 ° C. and added in 25 minutes. 16.8 g of bromine in 80 ml of concentrated hydrochloric acid. The slurry is heated in a water bath for one hour and then cooled in an ice bath for one hour. The reaction mixture is then filtered and the salt is washed with three fractions of ml of cold distilled water. After drying, the crude product is dissolved in 600 ml of distilled water, the solution is treated with 3.0 g of "Darco" and filtered on a bed of "Hyflo" to obtain a solution. The neutralization with concentrated ammonia gives a milky solution from which the product solidifies by cooling to C. After cooling for about 16 hours, the beige product obtained is filtered off, washed with cold distilled water and dried under vacuum for about 16 hours to obtain 12.0 g of the title compound, point of

melting 34.0-35.0 C.

  B) 2,2 '- [[2 - [(3-bromo-2,4,6-trimethylphenyl) amino] -

  2-oxoethyl] imino] bisacetic A suspension of 9.56 g of nitrilotriacetic acid is prepared in pyridine (dried over molecular sieves), excluding moisture (drying tube CaSO4) and heated to 50 C. add dropwise 5.11 g of acetic anhydride. The reaction mixture clears and is heated to 100 C. After maintaining the temperature for 40 minutes, the reaction mixture is cooled to

   C and slowly add a solution of 10.7 g of 3-

  bromo-2,4,6-trimethylaniline in 25 ml of dry pyridine.

  The reaction mixture is heated to 100 ° C. and after one and a half hours at this temperature, the solution is cooled in an ice bath. The reaction mixture is subjected to rotary evaporation to obtain a quasi-solid which is dissolved in 125 ml of 10% (weight / volume) sodium hydroxide. The basic layer is then extracted with two 100 ml portions of methylene chloride. Ml of distilled water is added to the basic layer, which is then brought to pH 3 with concentrated hydrochloric acid to obtain a precipitate. After cooling for about 16 hours, the crude product is filtered off, washed with cold distilled water and dried under vacuum at 40 ° C. The crude product is dissolved in 100 ml of 60% aqueous ethanol. treated with 3.0 g of "Darco" and hot-filtered on a bed of "Hyflo" to obtain a solution. Crystals precipitated, filtered and washed with three 25 ml portions of 50% aqueous ethanol, and dried under vacuum at 40 ° C. The reaction yielded 9.1 g of the title compound.

  title, mp 198-200 ° C, decomposition.

EXAMPLE 2

  2,2 '- [[2 - [(3 - [(3-bromo-2,6-diethyl-4-methylphenyl)) - acid

  amino] -2-oxoethyl] imino] bisacetic acid A) 3-Bromo-2,6-diethyl-4-methylaniline It is cooled to 5 ° C. in an ice-bath and with 1 ml of concentrated hydrochloric acid, and 1 63 g of 2,6-diethyl-4-methylaniline to obtain a suspension. We add drop by drop, in 30 minutes,

  1.59 g of bromine with 10 ml of concentrated hydrochloric acid.

  The reaction mixture was allowed to stir for 3.75 hours and 25 ml of distilled water was added. After cooling for 1.0 hour, the reaction mixture is filtered

  and washed twice with 25 ml of cold distilled water.

  After drying under vacuum for about 16 hours, the crude solid (2.3 g) is dissolved in 100 ml of 10% sodium hydroxide and extracted with a 150 ml fraction and another 100 ml fraction of sodium chloride. methylene. After drying over sodium sulphate, the methylene chloride solution is subjected to rotary evaporation to obtain

1.9 g of crude product.

  B) 2,2 '- [[2 - [(3-bromo-2,6-diethyl-4-methylphenyl)) -

  amino] -2-oxoethyl] imino] bisacetic acid A suspension of 1.34 g of nitrilotriacetic acid is prepared in 15 ml of dry pyridine (dried over molecular sieves) and heated to 46 ° C. acetic anhydride (rinsing with 1 ml of pyridine) and the solution is heated to 100 ° C. After heating for half an hour, the solution is allowed to cool to 46 ° C. and

  slowly add a solution of 1.7 g of 3-bromo-2,6-

  crude diethyl-4-methylaniline in 6 ml of pyridine. This solution is heated at 100 ° C. for 2 hours, cooled, and evaporated on a rotary apparatus to obtain a pasty product. This product is dissolved in 25 ml of 10% sodium hydroxide and the resulting solution is extracted twice with 25 ml portions of methylene chloride. The aqueous solution is diluted with 50 ml of distilled water, brought to pH 3.0 with concentrated hydrochloric acid, and cooled for about 16 hours. Filtration gives a solid which, after drying for 3 hours at 60 ° C. under vacuum, gives 1.4 g of crude product. Recrystallization from 25 ml 50% ethanol gives 1.04 g needles, mp.

194.5-195.5 C.

EXAMPLE 3

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

  imino] bisacetic A suspension of 4.78 g of nitrilotriacetic acid is heated at 60 ° C. in 40 ml of dry pyridine (dried over molecular sieves). 2.55 g is slowly added

  of acetic anhydride and the solution is heated to 100.degree.

  After heating for half an hour, the solution is cooled to 40 ° C. and a solution of 8 g of 3-iodo-4-methylaniline in 20 ml of pyridine is added over 25 minutes.

  dried. The solution is heated at 100 ° C. for 1.0 hour.

  The reaction mixture was cooled and rotoevaporated to give a residue which was dissolved in 65 ml of 10% sodium hydroxide. This solution is extracted twice with 50 ml portions of methylene chloride diluted with 100 ml of distilled water and heated to pH 3.2 with concentrated hydrochloric acid. The crude product is cooled for about 16 hours, filtered, washed twice with 50 ml portions of distilled water, and dried under vacuum at 40 ° C. The crude product (8.0 g) is recrystallized. ) after treatment with "Darco" to obtain 5.7 g of product, melting point

213.5-215.0 ° C (decomposition).

EXAMPLE 4

  2,2 '- [[2 - [(4-bromo-3-methylphenyl) amino] -2-oxoethyl acid] -

  imino] bisacetic A suspension of 9.56 g of nitrilotriacetic acid is heated at 55 ° C. in 80 ml of dry pyridine (dried over molecular sieves). 7.66 g is added

  of acetic anhydride and the solution is heated to 100.degree.

  After heating for half an hour, we cool

  solution at 55 ° C. and 9.30 g of 4-bromo-3-methyl-

  aniline with rinsing with 5 ml of pyridine. The solution is heated at 100 ° C. for 1.0 hour. The reaction mixture was cooled and rotary evaporated to give a pasty solid which was dissolved in 120 ml of aqueous ammonia (30 ml of concentrated ammonia in 90 ml of distilled water). The light brown solution is extracted with two 100 ml portions of methylene chloride and

  the door at pH 3 with 35 ml of concentrated hydrochloric acid.

  The white solid is filtered and washed with three fractions

2497197-

  25 ml of cold distilled water, and dried under vacuum for 2.75 hours at 60 C. The crude product (12.9 g) is recrystallized in 360 ml of 50% ethanol to obtain

  9.85 g of product, mp 206.5-209.0 C.

EXAMPLE 5

  2,2 '- [[2 - [(3-bromo-4-methylphenyl) amino] -2-oxoethyl acid] -

  imino] bisacetic A suspension of 4.78 g of nitrilotriacetic acid is prepared and heated at 50 ° C. in 40 ml of dry pyridine (dried over molecular sieves). 2.55 g of acetic anhydride are slowly added and the solution is heated to C. After heating for half an hour, the solution is cooled to 42 ° C. and 4.81 g of 3-bromo-4-methylaniline are slowly added. 5 ml of pyridine. The solution was heated to 1000 ° C. After heating for 2.0 hours, the reaction mixture was cooled and rotoevaporated. The substance obtained is dissolved in 10% sodium hydroxide and extracted twice with 50 ml portions of methylene chloride. The aqueous fraction is diluted with 100 ml of distilled water, brought to pH 3.2 with concentrated hydrochloric acid, and

  Cool for about 16 hours during the night.

  The reaction mixture is filtered and washed with cold distilled water. After drying for 3 hours under vacuum at 60 ° C., 7.41 g of crude product is obtained, mp 206.0-208.0 ° C. Recrystallization from 150 ml of 75% ethanol gives 6.4 g. solid, melting point

209.0-210.0 C.

EXAMPLE 6

  Compositions for complex formation with technetium-99m The table below shows examples of compositions of compounds of formula I with stannous fluoride as a reducing agent. These compositions are prepared by dissolving the ligand in 0.46 M sodium hydroxide to obtain a solution whose final pH is from 6 to about 7.5. To this solution was added 0.01 ml of a 70 mg / ml solution of stannous fluoride in 1 M hydrochloric acid, and the volume was brought to 5 ml with water for injection. The compositions in the following table have a

  preferred molar ratio of the ligand to tin of 150: 1.

BOARD

  Concentration (mg / ml) Coordinate Coordinate Fluoride pH __ __ stannous

  2,2 '- [[2 - [(3-bromo-2,4,6-trimethyl) -acetate

  phenyl) aminol] -2-oxoethyl] imino] bisacetic 48.6 0.14 6.76

  2,2 '- [[2 - [(3 - [(3-bromo-2,6-diethyl) -4-acid

  methylphenyl) amino] -2-oxoethyl] imino] -

bisacetic 51.9 0.14 5.99

  2,2 '- [2 - [(3-iodo-4-methylphenyl) amino] - acid

  2-oxoethyl] imino] bisacetic 50.4 0.14 7.55

  2,2 '- [[2 - [(4-bromo-3-methylphenyl) amino] - acid

  2-oxoethylimino] bisacetic 44.6 0.14 5.96

  2,2 '- [[2 - [(3-bromo-4-methylphenyl) amino] - acid

  2-oxoethyl] imino] bisacetic 44.9 0.14 7.39 no

Claims (10)

  1. Compound of formula: ## STR2 ## / "CH R2 (CH2) n -NH-CH2-N1CH2C-OH, 2I R3 R4 O   optionally in the form of a water soluble and pharmaceutically acceptable salt, wherein R1 and R4 are each, independently, a hydrogen atom or a methyl or ethyl radical; one of R 2 and R 3 is an alkyl radical of 1 to 4 carbon atoms and the other is a bromine or iodine atom; and n is 0, 1 or 2.   2. Compound according to claim 1, having the formula: O // \ Il, CH2-C-OH R2 -NH-C-CH 2-N 2 z4 \ CH2-C-OH, R R il1 3 4 O   optionally in the form of a water-soluble salt and pharmaceutically acceptable.   3. Compound according to claim 1 or 2, in   which R1 and R4 are both methyl radicals.   The compound of claim 1, 2 or 3, optionally in the form of a water soluble and pharmaceutically acceptable salt, wherein one of R2 and R3. is a methyl or ethyl radical.   5. Compound according to claim 1, which is   2,2 '- [[2 - [(3-bromo-2,4,6-trimethylphenyl) amino] -2-   oxoethyl] imino] bisacétique. 6. A compound according to claim 1, which is 2,2 '- [[2 - [(3-bromo-2,6-diethyl-4-methylphenyl) amino] r 2-oxoethylimino] bisacetic acid.   The compound of claim 1, which is   2,2 '- [E2 - [(3-iodo-4-methylphenyl) amino] -2-oxoethyl] -   imino] bisacétique. The compound of claim 1, which is   2,2 '- [[2 - [(4-bromo-3-methylphenyl) amino] -2-oxoethyl] -   imino] bisacétique. 9. The compound of claim 1, which is   2,2 '- [[2 - [(3-bromo-4-methylphenyl) amino] -2-oxoethyl] - imino] bisacétique.   A composition comprising a stannous reducing agent and a compound according to any one of Claims 1 to 9.