DK150302B - METHOD OF ANALOGUE FOR THE PREPARATION OF SPIRO-HYDANTOIN COMPOUNDS OR PHARMACOLOGICAL ACCEPTABLE BASES - Google Patents

Description

150302 i

The invention relates to an analogous method for preparing novel spirohydantoin compounds of the general formula I set forth in claim 1 which are particularly valuable because of their ability to control certain chronic complications resulting from diabetes mellitus (f. eg diabetic cataracts and neuropathy).

Numerous researchers in organic medicine chemistry have previously made various attempts to obtain new and better antidiabetic drugs for oral use. These experiments have mostly involved the synthesis and testing of various novel or inaccessible organic compounds, especially among the sulfonylureas, in order to determine their ability to lower their blood sugar levels (i.e., glucose levels) when administered orally. However, in the research of newer and more effective antidiabetic drugs, little is known about the effect of other organic compounds in preventing or stopping the development of certain chronic complications associated with diabetes, such as diabetic cataracts, neuropathy and retinopathy.

K. Sestanj et al. U.S. Patent No. 3,821,383, nevertheless, states that certain aldose reductase inhibitors such as 1,3-dioxo-1H-benz [d, e] -isoquinoline-2 (3H) -acetic acid and certain of its closely related derivatives are useful for these purposes, although these particular compounds are not known to be hypoglycemic in themselves. These particular aldose reductase inhibitors all act by inhibiting the action of the enzyme aldose reductase, which is primarily responsible for regulating the reduction of aldoses (such as glucose and galactose) to the corresponding polyols (such as sorbitol and galactitol) in the human body. In this way, the unwanted accumulation of galactitol in the eye lens of galactosemia patients and of sorbitol in the eye lens, in the peripheral nerve marrow and in the kidney in various diabetic patients can be prevented or, where appropriate, reduced. Accordingly, these compounds are definitely of value as aldose reductase inhibitors for the control of certain chronic, diabetic complications, including those affecting the eye, as it is well known in medical science that the presence of polyols in the eye lens inevitably leads to cataract formation. a more or less simultaneously developed loss of lens clarity.

According to the present invention, it has now surprisingly been found that the spirohydantoin compounds of formula I prepared by the invention are particularly useful when used in therapy as aldose reductase inhibitors to control certain chronic diabetic complications of the patients to whom they are administered. These compounds are all potent aldose reductase inhibitors and therefore have the ability to markedly reduce, even inhibit the sorbitol accumulation in the eye lens and in the peripheral nervous system in various diabetic patients.

The novel compounds of formula I comprise spirohydantoin compounds of formula: 0 mr-f x oJLf

x2J * sJ

2 wherein X is hydrogen and X is fluoro, hydroxy or 5'- or e'-alkoxy of 1-4 carbon atoms, or X and X individually are alkoxy of 1-4 carbon atoms or together -OCE -, dg base salts thereof with pharmacologically acceptable cations.

The novel compounds of formula I also include spirohydantoin compounds of formula: ΗΒΓ— γ3 / \ X * wherein X is hydrogen and X is fluorine or alkoxy 3 4 with 1-4 carbon atoms, or X and X each represents chlorine or methyl, and Y represents oxygen or sulfur and base salts thereof with pharmacologically acceptable cations.

Finally, the novel compounds of formula I also comprise spirohydantoin compounds of formula:

WL

X * Q o 5 "wherein X means hydrogen or fluorine and Q means -S- or -S-,

II II

o o and base salts thereof with pharmacologically acceptable cations.

Of particular interest in this connection are such typical and preferred compounds prepared by the process of the invention as: 6-fluoro-spiro [chroman-4,4'-imidazolidine] -2 ', 5'-dione, 6.7-dichloro spiro [chroman-4,4'-imidazolidine] -2 ', 5'-dione, 6.8-dichloro-spiro- [chroman-4,4'-imidazolidine] -2', 5 * -dione, 6'-fluoro -spiro [imidazolidine-4,4'-thiochroman] -2,5-dione and 6 ', 7'-dichloro-spiro- [imidazolidine-4,4'-thiochroman] -2,5-dione.

These particular compounds are all potent in their aldose reductase inhibitory capacity, and they are also extremely effective in reducing the sorbitol level in the sciatic nerve and in the lens of diabetic patients, and the galactitol level in the eye lens of galactosemic patients to a surprisingly high degree.

4 150302

The process according to the invention is characterized by the characterizing part of claim 1.

The reaction of the carbonyl ring compound with alkali metal cyanide and ammonium carbonate under (a) is usually carried out in the presence of a reaction inert polar organic solvent in which both reaction components are mutually miscible. Preferred organic solvents for use in this connection include cyclic ethers such as dioxane and tetrahydrofuran, lower alkylene glycols such as ethylene glycol and trimethylene glycol, with water miscible lower alkanols such as methanol, ethanol and isopropyl alcohol, as well as N, N-di ( lower alkyl) lower alkanolamides such as Ν, Ν-dimethylformamide, N, N-diethylformamide, and Ν, Ν-dimethylacetamide, etc. The reaction is usually carried out at a temperature in the range of from 20 ° C up to approx. 120 ° C for a period of time between 2 hours and approx. 4 days.

Although the amount of the reaction components contained in the reaction may vary to some extent, it is preferred to use at least a modest molar excess of the alkali metal cyanide relative to the carbonyl ring compound starting material to obtain the maximum yield. Upon completion of the reaction, the desired product is readily isolated in a conventional manner, e.g. by first diluting the reaction mixture with water (boiling if necessary) and then cooling the resulting aqueous solution to room temperature, followed by acidification leading to the desired spirohydantoin compound in the form of a precipitate which is easy to isolate.

The compounds of formula I wherein A has the meaning V where 2 X is H and X is 6'-hydroxy are usually preferably prepared by first preparing the corresponding alkoxy compounds 2 where X is 6'-alkoxy of 1-4 carbon atoms. and then simply convert the latter into the desired hydroxy compounds by cleavage of the ether moiety by known techniques.

5 150302

According to variant (b) of the process of the invention, the compounds of formula I wherein A has the meaning VIII, wherein Q is SO or SC 2, can be prepared from the corresponding sulfides simply by oxidizing these by commonly known methods. For example, the use of sodium periodate leads to the formation of the sulfoxides, while peroxyacids such as peracetic acid, perbenzoic acid and m-chloroperoxybenzoic acid are preferably used if the corresponding sulfones are to be prepared.

The starting materials required for the process of the invention consist mostly of well-known compounds which are either readily commercially available, such as 1-indanone and 6-chloro-4-chromanone, etc., or which the person skilled in the art can readily synthesize based on generally known chemicals and using conventional organic synthesis methods. For example, 6-fluoro-4-chromanone is prepared by condensing p- (p-fluoro-phenoxy-propionic acid in the presence of polyphosphoric acid, while 6,7-dichloro-thiochroman-4-one is prepared by condensing p- (3,4-di -chlorophenylthio) propionic acid in the presence of concentrated sulfuric acid.

In both cases, the organic starting acid is derived from commercially available compounds.

The chemical bases used as reactants of the present invention to form the aforementioned pharmacologically acceptable base salts are those which form non-toxic salts with the various acidic spirohydantoin compounds described herein, such as 6-fluoro spiro [chroman-4,4'-imidazole-oxazolidine] -2 ', 5'-dione. These particular non-toxic base salts are of such a nature that their cations can be said to be substantially non-toxic in the large dose range in which they are administered. Examples of such cations include sodium, potassium, calcium and magnesium. These salts can be readily prepared by simply treating the aforementioned spirohydantoin compounds with an aqueous solution of the desired pharmaceutically acceptable cation, and then evaporating the resulting solution to dryness, preferably under reduced pressure. Alternatively, they may be prepared by admixing lower alkaline solutions of the above compounds in acid form 6 to the desired alkali metal alkoxides and then evaporating the resulting solution to dryness in the above manner. In both cases, stoichiometric amounts of the reaction components must be used to ensure the completion of the reaction and the maximum production yield with respect to the desired final product.

As previously stated, all of the spirohydantoin compounds of the invention are readily adapted for therapeutic use as aldose reductase inhibitors to control chronic diabetic complications due to their ability to reduce the sorbitol level in the eye lens to a statistically significant extent. Thus, 6-fluoro-spiro (chroman-4,4'-imidazolidine) -2 ', 5'-dione, a typical and preferred active compound of the invention, has been shown to be capable of constant control ( i.e., inhibiting) the formation of significantly elevated sorbitol levels in diabetic rpt when administered orally at dosage levels of 0.75-20 mg / kg, without showing any evidence of toxic side effects. Other compounds of the present invention exhibit similar results. All the compounds described herein prepared according to the invention can further be administered either orally or parenterally in accordance with the present purpose, without causing any significant adverse pharmacological side effects to the patient to whom they are administered. The compounds are usually administered in doses ranging from 0.1 mg to approx. 10 mg per kg body weight per day, although variations will necessarily occur depending on the patient's guard and. mode and of the particular mode of administration selected.

In connection with the use of spirohydantoin compounds of the present invention for the treatment of diabetic patients, it should be noted that these compounds can be administered either alone or in combination with pharmaceutically acceptable carriers, and by any of the aforementioned methods of administration. , and such administration may be performed both in single doses and in multiple doses daily.

7 150302

The effect exerted by the compounds of the present invention as agents for controlling chronic diabetic complications is determined by their ability to successfully pass one or more of the following standard biological and / or pharmacological tests, namely: (1) measuring their ability to inhibit the enzyme activity exerted by isolated aldose reductase; (2) measuring their ability to reduce or inhibit sorbitol accumulation in the sciatic nerve of acute streptozotocin-treated (i.e., diabetic) rats; (3) measuring their ability to reduce already elevated sorbitol concentration levels in the sciatic nerve and eye lens of chronic streptozotocin-induced diabetic rats; (4) measuring their ability to prevent or inhibit galac titol formation in the eye lens of acute galactosemic rats, and (5) measuring their ability to delay cataract formation and to reduce the degree of lens obscurity in chronic galactosemic rats.

The following preparations illustrate the preparation of the starting materials, while the following examples illustrate the process of the invention.

PREPARATION A

A mixture of 3 »5 g (0.019 mol) of p- (p-fluorophenoxy) propionic acid [Finger et al., Journal of The American Chemical Society, Vol. 81, page 94 (1959)] and 40 g of polyphosphoric acid were heated on a steam bath for 10 minutes and then poured into 300 ml of ice water. The resulting aqueous mixture was then extracted with three separate portions of ethyl acetate, and the combined organic layers were then washed with dilute aqueous sodium bicarbonate solution and then with water, followed by drying over anhydrous magnesium sulfate. After removal of the desiccant by filtration and of the solvent by evaporation under partial vacuum, finally an evaporation residue was obtained which was then recrystallized from ethanol to give 2.93 g (93%) of pure 6-fluoro-4- chromanone, mp 114-116 ° C.

Elemental analysis:

Calcd for C₂ &H₂PO₂, H₂O: C 63.34 - H 4.43

Found s C 63 »24 - H 4.15 ·

PREPARATION B

To a solution of 12.5 g (0.07 mol) of 3,4-dichlorobenzene thiol (available from Aldrich Chemical Company, Inc., Milwaukee, Wisconsin) in 35 ml of 2N aqueous sodium hydroxide and 5 ml of ethanol was added an ice cold solution consisting of 7.6 g (0.07 mol) of β-chloropropionic acid (also available from Aldrich) and 8.6 g (0.07 mol) of sodium carbonate monohydrate dissolved in 50 ml of water.

The reaction mixture thus formed was then heated on a steam bath for 2 hours, cooled to room temperature (about 25 ° C) and extracted with ethyl acetate to remove any impurities. The remaining aqueous portion was then poured into 300 ml of ice-cold 3 N hydrochloric acid and the precipitated solid was isolated on suction filter. After washing out the latter reaction product with water, air drying to constant weight and recrystallization from ethyl acetate / n-hexane. yielded 11.4 g (65%) of 3 - (3,4-dichlorophenylthio) propionic acid, mp 70-72 ° C.

Elemental analysis:

Calcd for C CHHCl₂S: C 43.04 - H 3.21

Found. . : C 43.13 - H 3.25.

A solution of the above product in concentrated sulfuric acid was prepared by adding 5.0 g (0.02 mol) of β- (3,4 ^ ΐο1ι1θΓρ3ιβ ^ 1-thio) propionic acid to 50 ml of ice-cold concentrated sulfuric acid, stirring was continued stirring. maintained throughout the addition period.

The resulting solution was then stirred at 0 ° C for 20 minutes and finally at room temperature for a further 20 minutes. The whole reaction mixture was then poured into 300 ml of ice / water mixture and the solid precipitate was isolated by suction filter, washed with water and air dried to constant weight. Recrystallization from ethanol gave a yield of 2.5 g (54 $) of pure 6,7-dichloro-thiochroman-4-one, mp 134-136 ° C.

Elemental analysis:

Calculated for C 9 H 6 Cl 120 S: C 46.37 - H 2.60 Found: C 46.34 - H 2.45.

EXAMPLE 1

A mixture consisting of 2.5 g (0.15 mol) of 6-methoxy-1-indanone (available from Aldrich Chemical Company, Inc., Milwaukee, Wisconsin), 1.5 g (0.23 mol) of potassium cyanide and 6.7 g (0.07 mol) of ammonium carbonate in 20 ml of ethanol was placed in a stainless steel pressure vessel and heated to 110 ° C for 20 hours.

After cooling to room temperature (equivalent to 25 ° C), the contents of the reaction vessel were diluted with 100 ml of water and then acidified to pH 2.0 with 6N hydrochloric acid. The reaction product thus prepared in the form of a precipitate was isolated by suction filter and later recrystallized from ethanol to give 0.49 g (14%) of pure 6'-methoxy-spiro [imidazo-lidin-4,1-indan ] -2,5-dione, m.p. 192-194 ° C.

Elemental analysis:

Calculated for C-j 2 H 2 N 2 O 3! C, 62.06; H, 5.21; N, 12.06

Found: C 61.94 - H 5.26 - N 12.01.

EXAMPLE 2

The procedure described in Example 1 was repeated with the exception that the starting material was 6-fluoro-1-indanone [Chemical Abstracts, Vol. 25, page 25873a (1961)], which was used in place of 6-methoxy-1-indanone, using the same molar ratios as previously used. In this case, the corresponding final product consisted of 6'-fluoro-spiro- [imidazolidine-4,11-indane] -2,5-dione, mp 255-257 ° C. The yield of pure final product was 4.6% of the theoretically achievable amount.

Elemental analysis:

Calculated for C CH ^ FNNO ^: C, 60.00; H, 4.12;

Found C 59.86 - H 4.33 - N 12.49.

EXAMPLE 3

The procedure described in Example 1 was repeated except that the starting material was 5,6-dimethoxy-1-indanone [Koo, Journal of the American Chemical Society, Vol. 75, page 1891 (1953)], which was used in place of 6-methoxy-1-indanone, using the same molar ratio as before. In this particular case, the final product produced consisted of 5,66 dimethoxy-spiro [imidazolidin-4,1,1-indane] -2,5-dione, mp: 246-248 ° C. The yield of pure final product was 48% of the theoretically achievable amount.

Elemental analysis:

Calculated for C 59.53 - H 5.38 - - - N 10.68

Found: C 59.26 - H 5.49 - N 10.54.

EXAMPLE 4

The procedure described in Example 1 was repeated except that the starting material was 5,6-methylenedioxy-1-indanone [Perkin and Robinson, Journal of the Chemical Society, Vol. 91, page 1084 (1907)], which was used in place of 6-methoxy-1-indanone, using the same molar ratio as before. IN

In this particular case, the final product produced consisted of 5 ', 61-methylenedioxy-spiro- [imidazolidine-4,1'-indane] -2,5-dione, mp 249-250 ° C. The yield of pure final product was 29% of the theoretically achievable amount.

Elemental analysis:

Calcd for C12 H10 N2 O4: C 58.53 - H 4.09 - N 11.38

Found: C, 58.44; H, 4.14; N, 11.25.

EXAMPLE 5

The procedure described in Example 1 was repeated except that the starting material was 5-methoxy-1-indanone (supplied by Aldrich Chemical Company, Inc., Milwaukee, Wisconsin), which was used in place of 6-methoxy-1-amine. indanone, using the same molar ratio as before. The final product prepared in this case consisted of 51-methoxy-spiro- [imidazoli-din-4,1'-indane] -2,5-dione, mp 167-169 ° C. The yield of pure final product was 19% of the theoretically achievable amount.

Elemental analysis:

Calcd for C12 H12 N2 O3: C 62.06 - H 5.21 - N 12.06

Found: C 61.77 - H 5.23 - N 12.14.

EXAMPLE 6

The procedure described in Example 1 was repeated except that the starting material was 6-methoxythiochroman-4-one [Chemical Abstracts, Vol. page 7161c (1959)], which was used in place of 6-methoxy-1-indanone, using the same molar ratio as before. The final product prepared in this case consisted of 6'-methoxy-spiro- [imidazolidine-4,4'-thiochroman] -2,5-dione, m.p. 170-172 ° C. The yield of pure final product was 41% of the theoretically achievable amount.

Elemental Analysis: 12 150302

Calcd for ^ 12 ^ 12 ^ 2 ^ 3 ^: C 54.53 - Η 4.58 - N 10.61

Found: C 54.64 - H 4.67 ~ N 10.66 * EXAMPLE 7

The procedure described in Example 1 was repeated except that the starting material was 6,7-dichlorothiochroman-4-one (prepared as described in Preparation B) which was used in place of 6-methoxy-1-indanone, the same mole ratio was used as before. The final product produced in this case was 6 '- [- dichloro-spiro-timidazolidine [beta] -thiochroman] - 2,5-dione, m.p. 298-300 ° C. The yield of pure end product was $ 49 of the theoretically achievable amount.

Elemental analysis:

Calcd for C18 H18 Cl2 N2 ° 2S: C 43.58 - H 2.66 - N 9.24

Found: C 43.77 - H 2.85 - N 9.38.

EXAMPLE 8

The procedure described in Example 1 was repeated except that the starting material was 6-fluorothiochroman-4-one [Chemical Abstracts, Vol. 70, page 47335x (1969)], which was used in place of 6-methoxy-1-indanone, using the same molar ratio as before. The final product prepared in this case consisted of 6'-fluoro-spiro- [imidazolidine-4,4-thio-chroman] -2,5-dione, m.p. 200-202 ° C. The yield of pure final product was 60% of the theoretically achievable amount.

Elemental analysis:

Calculated for C1: LHgFN2O2S: C 52.37 - H 3.60 - N 11.11

Found: C, 52.36; H, 3.73; N, 11.05.

EXAMPLE 9 13 150302

A solution of 1.18 g (0.005 mole) of [alpha] -methoxy-spiro-6-imidazo-lidin-4,1,1-indan] -2,5-dione (prepared as described in Example 1) in 10 ml of methylene chloride was The mixture was cooled to -65 ° C and then added drop by drop to a solution consisting of 1.44 ml (0.015 mol) of boron tribromide dissolved in 10 ml of methylene chloride while the whole reaction mixture was kept stirring in a nitrogen atmosphere. The resulting mixture was allowed to reach room temperature (equivalent to 25 ° C) by removing the cooling bath, and then kept at room temperature for 7 hours. At the end of this step, 30 ml of water was added drop by drop and the separated organic layer was isolated and dried over anhydrous magnesium sulfate. After removal of the organic solvent (i.e., methylene chloride) by vacuum evaporation, an evaporation residue was obtained which was then recrystallized from ethanol to give 240 mg (22%) of pure 6'-hydroxy-spiro [imidazolidine-4.1'- indane] -2,5-dione, mp 253-255 ° C.

Elemental analysis:

Calc'd for n% 0 ^ 2 ^ 3: mp 54> H 4.62 - N 12.84

Found: C, 60.29; H, 4.66; N, 12.93.

EXAMPLE 10

A mixture consisting of 6.0 g (0.033 mole) of 6-methoxy-4-chromanone (GB Patent No. 1,024,645), 2.8 g (0.043 mole) of potassium cyanide and 8.26 g (0.086 mole) of powdered ammonium carbonate in 40 ml of ethanol was placed in a stainless steel pressure vessel and heated to 60 ° C in an oil bath for 24 hours. The reaction mixture was then diluted with 300 ml of water, boiled for 15 minutes and, after cooling to room temperature, acidified with 6 N hydrochloric acid. The reaction product thus prepared in the form of a precipitate was isolated on suction filter and then recrystallized from ethanol to give 2.6 g (32%) of pure 6-methoxy-spiro [chroman-4,4'-imidazolidine] -2 5'-dione, m.p. 170 - 172 ° C.

14 150302

Elemental analysis:

Calcd for C 12 H 12 N 2 ° 4: C 58.06 - H 4.87 - N 11.29

Found: C, 58.04; H, 4.98; N, 11.17.

EXAMPLE 11

The procedure described in Example 10 was repeated except that the starting material was 6-fluoro-4-chromanone (prepared as described in Preparation A) used in place of 6-methoxy-4-chromanone, using the same molar ratio as previously. The final product produced in this case consisted of e-fluoro-spiro-chromane [alpha] -imidazolidine], 5'-dione, mp 239-24 ° C. The yield of pure final product was 36% of the theoretically achievable amount.

Elemental analysis:

Calculated for C CH ^FN ^: C 55.93 - H 3.84 - N 11.86

Found: C, 55.54; H, 3.88; N, 12.12.

EXAMPLE 12

The procedure described in Example 10 was repeated except that the starting material was 6,7-dichloro-4-chromanone (disclosure No. 1 928-027) used in place of 6-methoxy-4-chromanone, the same mole ratio was used as before. The final product prepared in this case consisted of 6,7-dichloro-spiro [chroman-4,4, -imidazolidine] -2 ', 5'-dione, mp 263-265 ° C. The yield of pure final product was 8% of the theoretically achievable amount.

Elemental analysis:

Calculated for C CH HCl ^NpO ^: C 46.02 - H 2.81 - N 9.76

Found: C, 45.83; H, 2.94; N, 9.65.

EXAMPLE 15 t50302

The procedure described in Example 10 was repeated with the assumption that the starting material was 6,8-dichloro-4-chromanone [Huchle et al., Journal of Medicinal Chemistry, Vol. 12, page 277 (1969) ^, which was used in place of 6-methoxy-4-chromanone, using the same molar ratio as before. The final product prepared in this case consisted of 6,8-dichloro-spiro [chroman-4,4, -imidazolidine] -2 ', 5'-dione, m.p. 234 - 235 ° C. The yield of pure final product was 20% of the theoretically achievable amount.

Elemental analysis:

Calculated for C CH ^Cl₂NN: C 46.02 - H 2.81 - N 9.76

Pound: C 45.81 - H 2.74 - N 9.69.

EXAMPLE 14

A mixture consisting of 252 mg (0.001 mol) of 6'-fluoro-spiro [imidazolidine-4,4-thiochroman] -2,5-dione (prepared as described in Example 8) in 10 ml of methylene chloride together with 50 mg of 40 % aqueous solution of tetrabutylammonium hydroxide and 224 mg (0.01 mole) of sodium periodate in 5 ml of water was kept under stirring at room temperature (equivalent to 25 ° C) for 1 hour.

The solid precipitate thus obtained was then isolated by a suction filter and then recrystallized from ethanol (3 ml) to give 60 mg (22%) of pure 6'-fluoro-spiro [imida-zolidine-4.4 thiochroman] -2,5-dione-1, oxide, m.p. 289 - 291 ° C.

Elemental analysis:

Calculated for C CH ^FNNS: C 49.25 - H 3.38 - N 10.44

Found: c 49.27 - H 3.35 - N 10.35.

EXAMPLE 15 16 150302

To a suspension of 0.595 g (0.00236 mole) of 6'-fluoro-spiro [imi-dazolidine-4,4, -thiochroman] -2,5-dione (prepared as described in Example 8) x'SO ml of chloroform placed in a 250 ml three-necked, round-bottomed reaction flask, 1.00 g (0.00579 mole) of m-chloroperoxybenzoic acid was added in small portions over one hour.

The resulting slurry was kept under stirring at room temperature (equivalent to 25 ° C) for 36 hours and finally diluted with 500 ml of ethyl acetate. The yellow organic layer thus formed was then washed with four 50 ml portions of saturated aqueous sodium hydrogen carbonate solution, dried over anhydrous magnesium sulfate, filtered and the solvent removed in vacuo to give 0.50 g (74.5%) of crude 6'-fluorine. -spiro- [imi-dazolidine-4,4'-thiochroman] -2,5-dione-l *, 1'-dioxide in the form of a white crystalline evaporation residue. Recrystallization from ethanol / ethyl acetate / n-hexane then afforded the pure material (m.p. 179 - 180 ° C with decomposition) as the first product in the form of fine white crystals (yield 0.295 g) · Two additional recrystallizations from ethanol / ethyl acetate increased melting point of the assay sample to 184 - 186 ° C (with decomposition).

Elemental analysis:

Calculated for C C HHgFM ^S.0.50,500000 ^: C 47.55 - H 3.99 - N 8.53 Found: C 47.54 - H 3.93 - N 8.56.

EXAMPLE .16 ·

The procedure described in Example 15 was repeated except that 0.234 g (0.001 mole) of spiro [imidazolidine-4,4'-thiochroman] -2,5-dione and 0.426 g (0.00247 mole) of m-chloroperoxybenzoic acid were reacted with each other to give 0.20 g (75%) of pure spiro- [imidazolidine-4,4'-thiochroman] -2,5-dione-1 ', 1 dioxide. Recrystallization from methanol / ethanol / n-hexane led to the assay (m.p. 280 - 281 ° C).

17 150302

Elemental analysis:

Calcd for C 11 H 10 N 2 O 4 S: C 49.61 - H 3.78 - N 10.52

Found: C 49.82 - H 3.85 - N 10.19.

EXAMPLE 17

A mixture of 1.0 g (0.00549 mol) of thioindan-3-one-1,1-dioxide [Regit-z, Chemische Berichte, Vol. 98, page 36 (1965)], 0.613 g (0.0094 mol) of potassium cyanide and 21.9 g (0.021 mol) of ammonium carbonate in 14 ml of 50% aqueous ethanol were placed in a 50 ml round bottom flask and heated to 60 °. C for 48 hours under nitrogen cover. The reaction mixture was then diluted with 70 ml of water and a trace of solid was removed by filtration and the filtrate was then acidified with 6N hydrochloric acid. The precipitated product thus formed was filtered off, redissolved in 4N aqueous potassium hydroxide solution and finally acidified again with 6N hydrochloric acid.

The acidic mixture containing the reaction product was saturated with sodium chloride and then extracted with six 150 ml portions of freshly prepared ethyl acetate, and the organic layers thus formed were combined and dried over anhydrous magnesium sulfate. After removal of the desiccant by filtration and the organic solvent by vacuum evaporation, 0.50 g (36%) of pure spiro- [imidazolidine-4,3'-thioindane] -2,5-dione-11'-dioxide was obtained. mp 287 ° C (under decomposition) after two recrystallizations from ethanol / ethyl acetate / n-hexane.

Elemental analysis:

Calculated for C C ^Hq ^O₂S: C 47.61 - H 3.20 - N 11.11

Found: C 47.77 - H 3.28 - N 10.85.

EXAMPLE, 18 18 150302

A mixture of 2.75 g (0.01562 mol) of 6,8-dimethyl-4-chromanone [Chemical Abstracts, Vol. 58, page 13900c (1964)], 5.5 g (0.0538 mol) of potassium cyanide and 10.5 g (0.109 mol) of ammonium carbonate in 60 ml of 50% aqueous ethanol were placed in a 125 ml round bottom flask and heated at room temperature. using an oil bath to 65 ° C for 48 hours under nitrogen coverage. The reaction mixture was then cooled to room temperature (equivalent to 25 ° C) and filtered, and the filtrate thus obtained was extracted with 50 ml of diethyl ether. The resulting aqueous layer was separated and then acidified to pH 2.0 with 3N hydrochloric acid (cooling was required). The turbid mixture thus formed was then extracted with three 250 ml portions of ethyl acetate and the combined organic layers were re-extracted with three 50 ml portions of 4N aqueous potassium hydroxide solution. The mixed basic aqueous layers were again acidified to pH 2.0 with 3N hydrochloric acid in the same manner as described above and then saturated with sodium chloride prior to extraction with three 250 ml portions of freshly prepared ethyl acetate. The combined organic layers were then dried over anhydrous magnesium sulfate and filtered. Finally, after removing the solvent from the filtrate by vacuum evaporation, 2.50 g (65%) of 6,8-dimethyl-spiro- [chroman-4,4'-imidazolidine] -2 ', 5 * -dione, m.p. 185 - 190 ° C (during decomposition). Two recrystallizations from aqueous ethanol resulted in analytically pure compound (mp 188 - 189 ° C).

Elementary Analysis e:

Calculated for C CH H ^O CC 63.40 - H 5.73 - N 11.38

Found: C 63.05 - H 5.69 - N 11.33.

BIOLOGICAL TESTING

The spirohydantoin compounds listed below, prepared according to the preceding Examples 1-18, were tested for their ability to reduce or inhibit aldose reductase enzyme activity by the method described by S. Hayman et al. in Journal of Biological 19 150302

Chemistry, Vol. 240, page 877 (1965), and as modified by K. Sestanj et al. in U.S. Patent No. 3,821,383.

In all cases, the substrate used was partially purified aldose reductase enzyme derived from calf eyes. The results obtained for each compound are listed below in the form of percent inhibition of enzyme activity using the different concentration levels tested:

Percent inhibition (%)

Connection from _Λ 10 m 10 m 10 bm 10 m Example 1 97 61 17 1 Example 2 74 12 22 -1 Example 3 90 81 35 9 Example 4 92 67 25 3 Example 5 82 60 13 -10 Example 6 76 60 18 7 Example 7 67 84 76 69 Example 8 81 77 66 38 Example 9 93 31 11 -30 Example 10 100 92 35 7 Example 11 84 58 52 3 Example 12 59 96 91 84 Example 13 85 90 78 81 Example 14 87 80 64 16 Example 15 85 74 74 28 Example 16 94 69 31 "2 Example 17 81 64 22 4 Example 18 71 84 54 17

BIOLOGICAL TESTING II

The following spirohydantoin compounds prepared according to Examples 1-4 and 6-17 were tested for their ability to reduce or inhibit the sorbitol accumulation in the sciatic nerve of streptozotocin-treated (i.e., diabetic) rats following a procedure essentially described. in U.S. Patent No. 3,821,383. In the present study, the extent of sorbitol accumulation in the sciatic nerves was measured 27 hours after the onset of diabetes. The compounds were administered per Os at the indicated dosage levels 4, 8 and 24 hours after the streptozotocin was administered. The results thus obtained are listed in the following table, expressed as percent inhibition (%) exerted by the tested compound compared to the case where no compound was administered (i.e., the untreated animal, in which sorbitol levels normally rise from about 1%). 50 to 100 mmol per gram of tissue to as high as 400 mmol per gram during the 27-hour experimental period):

Percent inhibition (%) mg / kg.

Compound from 0.75 1.5 2.5 5.0 Example 1 6 54 Example 2 - - - 45 - Example 3 - - - 33 49 Example 4 9 Example 6 - - 26 Example 7 - - 59 - Example 8 13 45 74 - - Example 9 ---- 15 Example 10 - 24-- Example 11 45 72 - - - Example 12 64 Example 13 82 Example 14 - 35 _ Example 15 - - 47 68 - Example 16 28 - 12 - - Example 17 - - _ 5 _

BIOLOGICAL TESTING III

6-Fluoro-spiro [chroman-4,4 * -imidazolidin-Z ', 51-dione (prepared from Example 11) was tested for its ability to decrease already elevated sorbitol levels in streptozotocin-induced, diabetic rats after 2 weeks in this condition (ie in chronic condition), administering the above compound per os to the animals for 7 days. In this study, sorbitol was determined both in the sciatic nerve and in the eye lens. First, the animals were administered streptozotocin intravenously in amounts of 65 mg per day. kg. The animals then remained untreated for 2 weeks. At the end of the two weeks, a control group of 8 rats (control group I) was slaughtered to determine the base sorbitol level, while the remaining two groups of each 7 animals were either administered 6-fluoro-spiro [chroman-4.41 -imidazolidine] -21,5'-dione in the amount of 2.5 mg per kg twice daily, or simply water (control group II). After 7 days, the rats were slaughtered (3 hours after dosing) and it was found that while the sciatica nerve sorbitol levels in the control group (control group II) had risen slightly higher than the baseline levels and the eyelid sorbitol values had stabilized with respect to the baseline levels, significant reductions had occurred. in the sorbitol levels in both the sciatic nerve (68%) and the eye lens (71%) of the treated animals (ie, the animals that had received the above test compound).

BIOLOGICAL TESTING IV

The ability of 6-fluoro-spiro [chroman-4,4'-imidazolidine] -2'-dione to prevent or inhibit galactitol formation in acute galactosemic rats was determined by providing the above compound to the test animals through their food in a period of 7 days.

In this study, normal male rats were first divided into three groups of six animals and then fed a diet containing 30% galactose together with the study compound present at three different dosage levels. One group of animals received 6-fluoro-spiro [chroman-4,4, -imidazolidine] -2 ', 5'-dione in the amount of 10 mg per ml. and another group received 20 mg per kg. kg. A control group of nine animals was given a $ 30 galactose diet without any test compound. At the end of the 7 days, the eye lenses were removed for galactitol determination and it was found that while the polyol levels of the control group had risen from substantially non-determinable amounts to a value significantly above 30 micromoles per day. There was a very pronounced inhibition of the galactitol values in the rats receiving the test compound in their food with galactose at the two higher dose levels tested (72% at 20 mg / kg and 40% at 10 mg / kg, respectively).

BIOLOGICAL TESTING V

To determine the effect of 6-fluoro-spiro [chroman-4,4'-imidazolidine] ^ 1,5'-dione on the cataract formation at galactosemic state, rats were fed a 30% galactose diet with and without addition of said compound through 29 days, and eye examinations were routinely performed approximately twice a week during this time period. The test animals received the test compound mixed with the feed at concentration levels which resulted in approximate doses of 10 mg / kg and 20 mg / kg, respectively. The control animals received only the galactose diet (ie without the test compound).

After 8-14 days, lens cloudiness was found to develop in 90% of control animals' eyes compared to no cloudiness present in the rats receiving 6-fluoro-spiro- [chroman-4,4-imidazolidine] -2 ', 5'-dione at levels of either 10 mg / kg or 20 mg / kg as mentioned earlier. After 17 days, it was found that obscurity was present in 100% of control animals' eyes, whereas only 6% of eyes of rats receiving e-fluoro-spiro-Cchroman ™ - imidazolidine] -dione in the amount of 10 mg / kg, was attacked. Corresponding value found in rats receiving the test compound at level 20 mg / kg was 0%. This delay in cataract formation persisted in all treated groups until 22 days had elapsed, at which time lens obscurity was observed in more than 90% of the eyes of the animals receiving the test compound at the 10 mg / kg level.

However, in the rats receiving β-fluoro-spiro- [chroman-4,4'-imidazolidine] -2 ', 5'-dione in the amount of 20 mg / kg, a convincing delay in cataract formation was observed even after 29 days, as evidenced by the fact that only 37% of the eyes of the animals thus treated exhibited lens obscurity.

23 150302

BIOLOGICAL TESTING VI

The ability of β-fluoro-spiro- [chromosn-4,4, imidazolidine] -2, βS-dione to delay cataract development in rats is further elucidated using the experimental procedure described in Test V, with careful consideration of the extent of the lens in question. -uklarheder. In this study, the percentage of lens area involved was monitored throughout the 29 day trial period and the observed results serve as an index of the extent. In this way, after 17 days, 75% of the control lenses were found to have an area of no less than 10%. On the other hand, corresponding values of 6% and 0% were found, respectively, in the rats receiving 6-fluoro-spiro. -chroman- [4,4'-imidazolidine] -2,5,5'Hion in amounts of 10 mg / kg and 20 mg / kg. Indeed, the extent of lens blur in the treated groups was steadily smaller than that found in the control group, including the values found at the end of the 29-day trial,

Claims (4)

150302 An analogous process for the preparation of spirohydantoin compounds of the general formula: HN --- γ wherein A means, - ·> χ W <1 Lj - έο2, -1 - IV X2 'V X3 χ [l]] or j || | X x 5 is VIII 2 wherein X is hydrogen and X is fluorine, hydroxy or 5'-2 or G 2 -alkoxy of 1-4 carbon atoms, or X and X are respectively alkoxy of 1-4 carbon atoms or together 3 4 but means -OCH-O-, X means hydrogen, and X means Δ 3 4 fluorine or alkoxy of 1-4 carbon atoms, or X and X each represent chlorine or methyl, Y means oxygen 5 or sulfur, X means hydrogen or fluorine, and Q is O II -S or -S-, II II oo or base salts thereof with pharmacologically acceptable cations, characterized in that (a) a carbonyl ring compound of formula: A wherein A has the above is reacted with an alkali metal cyanide and ammonium carbonate and, if desired, a spirohydantoin compound of formula I wherein A has significant V where X is H and X is 6'-alkoxy of 1-4 carbon atoms are converted into a corresponding compound where X is 2H and X is 6'-hydroxy, or (b) a spirohydantoin compound of formula wherein X has the above meaning, it is oxidized to form a compound of formula I wherein A has the meaning VIII and, if desired, it under (a) or ( b) formed spirohydantoin compound is converted into a pharmacologically acceptable base salt thereof. Process according to claim 1, characterized in that the reaction of the carbonyl ring compound with alkali metal cyanide and ammonium carbonate under (a) is carried out in a reaction inert solvent at a temperature in the range of 20 to 120 ° C. A method according to claim 1 or 2, characterized in that A has the meaning VII, where X is Η, X is F and Y is O. 4. A process according to claim 1 or 2, wherein g is O, wherein A has the meaning Vil, where xJ is H, Xq is F, and Y is S.