WO1997008178A1

WO1997008178A1 - Novel bisphosphonates, process for their preparation and pharmaceutical compositions containing them

Info

Publication number: WO1997008178A1
Application number: PCT/IL1996/000087
Authority: WO
Inventors: Ivan Sergeievitch Alferiev; Eli Breuer; Gershon Golomb; Asher Ornoy
Original assignee: Yissum Research Development Co of Hebrew University of Jerusalem
Current assignee: Yissum Research Development Co of Hebrew University of Jerusalem
Priority date: 1995-08-23
Filing date: 1996-08-22
Publication date: 1997-03-06
Anticipated expiration: 1998-02-23
Also published as: AU6835796A; IL115041A0

Abstract

Bisphosphonate compounds, their preparation and pharmaceutical compositions which contain such compounds as active ingredients. Such compositions are generally administered per os and they are effective for treating irregularities of the calcium metabolism. Preferred compounds have a 2-aminopyrimidine type ring. Similar unsubstituted and substituted heterocyclic compounds were found to have a similar activity.

Description

NOVEL BISPHOSPHONATES , PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM

The present invention relates to novel compounds of the general formula

where Q designates -H or -NR¹R², where A designates a 5- or 6-membered heterocyclic ring which contains 1, 2 or 3 nitrogen atoms, zero, 1 or 2 oxygen atoms and which may contain a sulfur atom, which contains up to and including 3 double bonds,

where R¹ and R² are independently hydrogen, lower

alkyl, lower alkenyl, lower alkoxy, (di)alkylaminoalkyl, alkoxyalkyl and where the ring A may be substituted by one or more conventional substituents.

The invention further relates to pharmaceutical

compositions, preferably for oral application, which

contain an effective quantity of one or more compounds of the above formula.

The invention specifically relates to pharmaceutical

compositions for the prevention and treatment or

irregularities of calcium metabolism in mammals, and

especially in humans.

Other and further aspects of the invention will become apparent hereinafter. Preferred compounds and

compositions have a ring of the 2-aminopyrimidine type. BACKGROUND OF THE INVENTION

There are several pathological conditions that involve irregularities in calcium metabolism. Such are some bone related diseases as Paget's desease, osteoporosis as well as osteolysis in bone metastases. Bone

metastases present a major problem in many frequently occurring malignancies. Hypercalcemia, resulting from bone resorption, is a common and very important

complication of malignancy, causing most distressful symptoms, such as severe pain, spontaneous fractures, and may lead to a metabolic coma and death. Moreover, neoplastic cell-induced osteolysis may determine the localization and growth enhancement of the tumor. (G.R. Mundy, Bone, S. supp. 1, s9-5 16 (1987); Calcium in Biological Systems, R.P. Rubin, G.B. Weiss, and J.W.

Putney, Jr., eds. Plenum Press, N.Y. (1985)). Ectopic calcification is a seemingly opposite type of

pathological condition, characterized by the deposition for calcium phosphate in a number of clinically

important diseases as, for example, artherosclerosis, kidney and renal calculus, arthritis, and bioprostetic heart valve calcification, and implanted biomaterial calcification such as bioprostetic and prosthetic heart valves, vascular grafts, LVAD (Left ventricular assist devices), contact lenses and a total artificial heart.

The novel bisphosphonates, according to the present invention are useful in the treatment of the following diseases; Osteoporosis (including disuse and

postmenopausal osteoporosis); Hypercalcemia of

Malignancy, (Direct) anticancer effect; Heterotopic Ossification (Hip Arthroplasty, Spinal cord injury;

Myositis Ossifications); Page's disease;

Hyperphosphatemia (e.g. Diabetes). It can be seen that said compounds are useful not only for direct treatment of various diseases but also for treatment of the symptoms of the diseases (e.g.

Hyperphosphatemia or Hypercalcemia).

The compounds according to the present invention are also useful as diagnostics (e.g. Nuclear Medicine).

The compounds according to the present invention may possess also industrial applications which are listed below (R.L. Hilderbrand. The Role of Phosphonates in Living Systems, Chapter 7, page 172, CRC Press).

Adhesives; Agents for extraction, concentration, and purification of uranium, thorium, and plutonium;

Antioxidants; Antistatic agents; Blowing agents;

Catalysis; Corrosion inhibitors; Coupling agents;

Crystallization inhibitors; Dentifrice compositions; Deodorants; Detergent additives; Detergents for cleaning metal surfaces; Dye modifiers; Flame

retardant polymers; Flame retardants for textiles;

Fire retardants for synthetic fibers; Flotation agents; Fuel additives; Gelling agents; Hardening oil

composites; Heat and light stabilizers; Hydraulic fluid additives; Ion exchange resins; Lubricants;

Photography; Plasticizers; Polyester, polyethylene, and polycarbonate discoloration inhibitors;

Polyurethane additives; Rayon additives; Resin and plastic additives; Scale inhibitors; Settling

retardants; Sequestering agents; Solvent extraction; Suspending agents; Synthetic fiber preparation;

Viscosity modifiers; Wood fireproofing agents. Bisphosphonates are a relatively new class of drugs that have been developed for use in various metabolic

diseases of bone, the target being excessive bond resorption and inappropriate calcification and

ossification. (M.D. Francis and R.R. Markodam, in "The Role of Phosphonates in Living Systems", R.L.

Hilderbrand, ed. CRC Press, Boca Raton, Fla, 983, pp. 55-96; H. Fleisch, Bone, 1987, 8, Supp. 1, s23-s28). Recently, there have been reports of encouraging

clinical trials utilizing bisphosphonates to treat hypercalcemia in patients with breast cancer, myeloma, and bronchial carcinoma related osteolytic metastases, in addition to the established usage of bisphosphonates in Paget's disease and for diagnostic purposes in bone mapping. However, bisphosphonate therapy is frequently accompanied by severe side effects. Bisphosphonates have been also found highly potent both in inhibiting bioprosthetic heart valve calcification, and in

experimental arteriosclerosis, however, this was

accompanied by severe adverse effects on bone

development and overall sematic growth.

The currently used bisphosphonates all belong to the geminal type, in which the two phosphoryl groups are bound to the same carbon ("P-C-P"), and therefore may be viewed as pyrophosphate analogs in which the oxygen between the two phosphorus atoms is replaced by a carbon. From the results obtained in various clinical studies using bisphosphonates it appears that there still is a need for compounds which have better oral bioavailability, greater margin between the bone

resorption inhibiting effect and that inhibiting

mineralization, without an increase is toxicity. According to the present invention it was found that by linking nitrogen containing heterocyclics to the side chain of bisphosphonates highly active compounds are obtained. The favorable effect on bone turnover of such new compounds was uniquely associated with the net increase of normal bone.

Compounds belonging to this group have also shown to possess significantly improved bioavailibility.

SUMMARY OF THE INVENTION

The present invention relates to novel compounds of the general formula

where R¹ and R² are independently hydrogen, lower alkyl, lower alkenyl, lower alkoxy, alkoxyalkyland where the ring A may be substituted by one or more

conventional substituents.

where A designates a 5- or 6-membered heterocyclic ring which contains 1, 2 or 3 nitrogen atoms, zero, 1 or 2 oxygen atoms and which may contain a sulfur atom, which contains up to and including 3 double bonds,

where hydrogen, lower alkyl, lower alkenyl, or lower alkoxy (di)alkylaminoalkyl, alkoxyalkyl, and where the ring A may be substituted by one or more conventional substituents.

The invention further relates to pharmaceutical

compositions, preferably for oral application, which contain an effective quantity of one or more compounds of the above formula. The invention specifically relates to pharmaceutical compositions for the prevention and treatment or irregularities of calcium metabolism in mammals, and especially in humans.

compositions have a ring of the 2-aminopyrimidine type.

The invention further relates to a process for the production of such bis-phosphonate compounds.

Advantageously a suitable vinylidene-bis-phosphonic acid hydrate, or corresponding higher homologue, is reacted with a suitable heterocyclic compound, as herein defined, and purifying the product.

The invention further relates to pharmaceutical

compositions for regulating the calcium metabolism of mammals, and especially humans, which contain as active ingredient a compound according to the present

invention. The main route of application is the oral route and unit dosage forms for oral administration contain for about 1 mg/kg to about 30 mg/kg of the active compound, and preferably from about 3 mg/kg to about 10 mg/kg of such bisphosphonate compound.

The invention is illustrated by means of a detailed example, it being understood that on the basis of this example it is possible to prepare a wide variety of compounds as herein described.

Preparation of 2-(2-aminopyrimidinio)-ethylidene-1,1-bis-phosphonic acid betaine (ISA 13-1, 1).

A mixture of vinylidene-bis-phosphonic acid hydrate 10.0g, containing 9.40g, 50.0 mmol of anhydrous acid), 2-aminopyrinidine (10.0g, 105.0 mmol) and water (6 ml) was placed on a bath with temperature 100°C and heated with stirring for 80 mins. The yellow brown mixture was diluted with water (200 ml), decolorized with charcoal and, after additional dilution with water to 600 ml, passed through a column with cationite Dowex-50, H± form. The eluate was concentrated in vacuo to a crystalline slurry (32g), diluted with methanol (40 ml) and allowed to stand at room temperature for complete crystallization with periodical rubbing. The crystals of I were filtered off, washed with a mixture of

methanol (20 ml) and water (10 ml), then with methanol and air-dried. Yield of I was 12.41 g (88% based on vinylidene-bis-phosphonic acid). The product was purified by dissolving in water (600 ml) at 50 - 60°C and the following concentration in vacuo. ¹H-NMR (D₂O + Na₂CO₃, pH ca. 7), 6, ppm; 2.20

(tt, 1H, CH, JPH - 21 Hz, JHH - 6 Hz), 4.42 (td, 2H,

CH₃, JPH - 14 Hz, JHH - 6 Hz), 6.95 (dd, 1H, H⁵, J1

- 7 Hz, J2 - 5 Hz), 8.31 (dd, 1H, H⁴, J1 - 7 Hz, J2 - 1 Hz), 8.62 (dd, 1H, H⁶, J1 - 5 Hz, J2 - 1 Hz) 31p

NMR (D₂O + Na₂CO₃, pH ca. 7), 6, ppm; 15.3 (dt, Jd

- 21 Hz, Jt - 14 Hz.

Additional compounds prepared by the same method:

2-(2-methylaminopyrimidinio)-ethylidene-1,1-bisphosphonic acid obtained from 2-methylaminopyrimidine in 98% isolated yield. NMR: P-31 15.4 ppm (double triplet, J = 22 Hz, (d) J = 14 Hz (t)).

Proton: 2.42 (1H, tt, J = 22 Hz, J = 6 Hz); 3.12 (3H, s); 4.50 (2H, td, J = 14 Hz (t), J = 6 Hz (d); 7.00 (1H, dd, J = 6 Hz, and J = 5 Hz); 8.41 (1H, dd J = 6 Hz, and J = 2 Hz); 8.79 (1H, dd J = 5 Hz, and J = 2

Hz).

2-(2-aminothiazolic)ethylidene-1,1-bisphosphonic acid obtained from 2- aminothiazole in 95% isolated yield.

NMR: P-31 15.2 ppm (double triplet, (J = 21 Hz (d), J 14 Hz (t).

2-(2-Aminopyridinio)-ethylidene-1,1-bisphosphonic acid betaine:

2-(3-Hydroxypiperidinyl)-ethylidene-1,1-bisphosphonic acid:

2-(1-Imidazolyl)-ethylidene-1,1-bisphosphonic acid:

2-(1-Pyrrolidiny1)-ethylidene-1,1-bisphosphonic acid:

2-(3-Methyl-1-imidazolio)-ethylidene-1,1-bisphosphonic acid betaine:

2-(2-Methyl-1-pyraazolio)-ethylidene-1,1-bisphosphonic acid betaine:

In a similar manner, with a variety of unsubstituted and substituted heterocyclic compounds, instead of 2-amino-pyrimidine, there were prepared in an analogous manner corresponding compounds which were purified as set out in Example 1. Biological Experiments - Subcutaneous Administration.

One-month-old rats of the Sabra strain (weighing 90-100 g) were treated daily (for 2 weeks) by subcutaneous injections with substances No. ISA 13-1, (6 mg/kg).

Controls were treated with saline (0.1 ml/100g body weight). After 2 weeks, the animals were sacrified. One tibia was dried weighed, ashed at 850°C and the Ca, P and Mg contents were determined. The other tibia was fixed in 10% buffered formaldehyde, decalcified in 4% formic acid, and embedded in glycol methacrylate. Two-three micron thick longitudinal sections were stained by toluidine blue and examined (semiquantitative analysis) by light microscopy. The results of chemical analysis fo the bones show that compound ISA 13-1 increased significantly (by 20%-40%) bone weight, ash weight and mineral content. Microscopical examination of the tibias showed a marked increase in the amount (both length and number) of metaphysaal bone trabeculas following treatment with substance ISA 13-1.

The most important microscopical finding is the fact that the new substance did not induce rickets. Its antiresorptive effect resulted in a net increase of normal fully mineralized metaphyseal bone trabeculae. This fact indicates that ISA 13-1 is a much more potent compound/drug than Pamidronate or any related

bisphosphonate.

In addition, there was no significant change in the blood levels of Ca in animals treated by ISA 13-1 as compared to controls. There was no clinical signs of toxicity. Oral Administration

Bisphosphonate ISA 13-1 was administered orally daily for 2 weeks by intragastric intubation to one month old rate weighing 100 g. in doses of 5 or 30 mg/kg. In parallel, Pamidronate was given orally in identical doses. Each group consisted of 8 rats. After 2 weeks the animals were sacrified and blood was removed for Ca and alkaline phosphates determination. The tibias were removed. One bone was used for the determination of ash weight, Ca, P, and Mg content, while other was fixed and embedded in glycol-methacrylate and the longitudinal sections were examined by light microscopy.

The results of the chemical studies showed that ISA 13-1 at the higher dose significantly increased bone and ash weight, and Ca and Mg content. The lower doses of ISA 13-1 had no effect on bone mineral content, but

increased serum Ca and alkaline phosphatase.

Pamidronate in the higher dose of 30 mg/kg also

increased bone ash weight and Ca content while 5 mg/kg had no effect.

Significent histological changes of the tibias were induced by ISA 13-1 in both doses. There was a

significant increase in the length of metaphyseal bone trabeculas and a very significant increase in the amount of bone as opposed to bone marrow. There was also a slight increase in the amount of cartilage in the metaphysis, implying slight rickets. Pamidronate in both doses also increased the length of the metaphyseal trabeculas but they were mainly composed of calcified cartilage without any significant increase in the amount of bone (when compared to bone marrow). Pamidronate also decreased the height of the growth plate, mainly because of a reduction in the amount of hypertrophic cartilage in the lower part of the growth plate. This may imply some direct negative effect of Pamidronate on the growth apparatus of long bones. In conclusion, substance ISA 13-1 seems to be very

effective orally in increasing the amount of bone in young growing rats.

A number of analogous heterocyclic nitrogen-containing compounds were evaluated as to their biological activity and the results demonstrated a similar degree of activity.

Claims

CLAIMS :

1. A compound of the general formula

where Q designates -H or -NR¹R²,

where R¹ and R² are independently hydrogen, lower alkyl, lower alkenyl, lower alkoxy, (di)alkylaminoalkyl, alkoxyalkyl and where the ring A may be substituted by one or more conventional substituents.

2. A compound according to claim 1, where A

designates a pyrroline, pyrrolidine, pyrazole,

pyrazoline, pyrazolidine, imidazole, triazole, pyridine, thiazole, oxazole, isoxazole, pyrazine, pyridazine and their partially or fully reduced derivatives, which are substituted as defined in claim 1.

3. A compound according to claim 1, of the formula

where R¹ and R² are a hydrogen, loweralkyl, lower alkoxy, alkoxyalkyl, (di)alkylaminoalkyl, lower alkynyl, and where the pyrimidine ring may be substituted by one or more conventional substituents.

4. A compound according to claim 1, where the -NR¹R² group is in the 2-position.

5. A compound according to claim 1 of the formula:

6. A compound according to claim 1 of the formula:

7. A compound according to claim 1, where A is of the formula:

8. A process for the production of compounds defined in any of claims 1 to 7, which comprise reacting a suitable form of vinylidene-bis-phosphonic acid with the desired heterocyclic compound and purifying the obtained product.

9. A process according to claim 8, for the

production of the compound claimed in claim 5, which comprises reacting vinylidene-bis-phosphonic acid hydrate with amino-pyrimidine, and purifying the product.

10. Process for the production of the compound defined in claim 1, substantially as hereinbefore described.

11. A pharmaceutical composition containing as active ingredient a sufficient quantity of a compound claimed in any of claims 1 to 7.

12. A composition according to claim 11, where the compound is as claimed in claim 5 or 6.

13. A pharmaceutical composition for oral

administration, for the treatment of irregularities of calcium metabolism in mammals, including humans, comprising an effective quantity of a compound claimed in any of claims 1 to 7.

14. A composition according to any of claims 11 to 13, in unit dosage form, containing from about 3 mg/kg to about 10 mg/kg of the active compound.

15. Oral pharmaceutical compositions for the

treatment of irregularities of calcium metabolism, and for the prevention of such irregularities, based on bisphosphonates herein defined, substantially as herein described.