HYDRAZONES AND THIAZOLIDINONES DERIVED FROM DIFLUNISAL

Technical Field

The present invention is related to original hydrazide-hydrazone and 4- thiazolidone compounds gained from the condensation of diflunisal hydrazide with substitute aldehydes obtained from Diflunisal (2',4'-Difluoro-4-hydroxybiphenyl-3- carboxylic acid) which is a medicine which has a nonsteroidal anti-inflammatory effect ().

Prior Art

Medicines with non-steroidal anti-inflammatory effects (NSAID) are used to treat inflammation. These groups; of medicines, inhibit COX-1, COX-2 and COX-3 at different ways which are isofo rms of the cyclooxygenase enzyme which catalyzes the conversion of the arachidonic acid to prostaglandins. Diflunisal, is an active substance which is a derivative of a weak acidic difluorophenyl salicylic acid. When the pharmacological effects are compared it has been determined that it is more effective and less toxic than medicine such as salicylic acid and indomethacin.

Many studies have been carried out regarding hydrazide-hydrazones and anticonvulsant, antidepressant, antimalarial, antiviral, vasodilator, antimicrobial and antitumoral effects have been seen in compounds with such structures. Due to this significant information, the synthesis of hydrazide-hydrazones has not lost its importance.

It has been determined that [2,3-d]pyrimidine-4-yl hydrazone analogues were effective against HCT116 colon cancer cells in Bioorg. Med. Chem., 23:7850-7860, 2009, that the hydrazones having 20 μΜ concentration synthesized via ribavirin were effective against A549 lung cancer cells in Carbohydr Res, 344(11): 1270-1275, 2009, that 2-phenylindol-3-carb aldehyde hydrazones provided effective inhibition against MDA-MB 231 and MCF-7 breast cancer and moreover prevented the proliferation of U-373 MG glioblastoma cells, in Bioorg. Med. Chem., 16(12): 6436- 6347, 2008, and thai synthesized N-substitutebenzylidene-3,4,5- trimetoxybenzohydrazones showed antitumor efficiency according to Bioorg. Med. Chem. Lett., 16(19):5036-5040, 006. In the recent years anti HCV effects have been determined on novel compounds comprising hydrazide-hydrazone according to, Arch. Pharm. (Weinheim), 339(l):14-23, 2006', and Marmara Pharm. J. 17:26-34, 2013.

This information is still up to date and a focus of attention of researchers, and the studies carried out on said groups are still being continued. It is known that the activity of the compounds within the hydrazide-hydrazone structure is related to the active pharmacophore group (-CONH-N=CH-). Hydrazides form hydrazone from aldehyde/ketones and as a result of condensation with mercaptoacetic acid of this hydrazones, compounds comprising 4-thiazolidone structures are obtained. 4- Thiazolidones are thiazolidine derivatives that carry carbonyl groups at 4-locations, and it has been noted in several studies conducted until today that they have antibacterial, antifungal, anticonvulsant, anticancer, and anti-tubercular activities.

It has been determined tha synthesized 2-[2,2-bis(4-chlorophenyl)ethyl]-2-(4- chlorophenyl-4-thiazolidone compound, inhibited at the rate of 52-91% in melanomas, colon and renal cancers according to Eur. J. Med. Chem, 37: 63-67, 2002, and that 2-aryl-4-oxo-thiazolidone-3-yl amides had an antiproliferative effect in prostate cancer cells according to Bioorg.&Med. Chem. Lett., 14: 5289-5293, 2004, and that synthesized aminoacyl 4-thiazolidone derivatives have antitumoral effects against S-180 sarcoma cells according to Biomed. Pharmacother., 60(3):121- 126, 2006.

Hepatitis C virus (HCV) which is a single stranded RNA virus from the Flaviviridae family is an important human pathogen which threatens the world's population with diseases such as chronic hepatitis, cirhosis, hepatocelular carsinoma and chronic liver diseases. Nowadays there is no protective vaccine which can be used when treating this virus, whi ch causes a severe threat against human health, as the HCV treatment carried out with ribavirin combined with interferon-d, has severe side effects. Front. Biosci., have found out in 13: 3857-3868, 2008, that 2',4'- Difluoro-4-hydroxybiphenyl-3-carboxylic acid[2-(2-fluorophenyl)-4-thiazolidinon-3- yl]amid derivative with 48 μΜ IC50 value was the most effective derivative.

The DNA gyrase enzyme plays a very important function role in the development of the replication slage in bacteria The inhibition of this enzyme, stops the replication of DNA and kills bacteria. As the Hydrazide-hydrazone and the antibacterial effects of 4-thiazolidones are known, the studies to be carried on the DNA-gyrase enzyme will provide a new point of view.

As the anticancer and HCV effects of the compounds comprising Hydrazide- hydrazone and 4-thiazolidone structures have been determined and as such studies carried out are low in number, it has been thought that there was a need to synthesize new anticancer and hepatitis-C NS5B polimerase enzyme inhibitors via diflunisal. The findings in literature have shown us a new path in order to develop new diflunisal hydrazide-hydrazones and 4-thiazolidinones that could have various biological activities.

Description of the Invention

In this invention, diflunisal hydrazide has been synthesized via diflunisal active agent which is a carboxylic acid derivative and new hydrazide-hydrazones and 4- thiazolidones have been obtained with the hydrazide. As it can also be seen in the synthesis schemes, 2',4'-difluoro-4- hydroxybiphenyl-3 -carboxylic acid methyl ester, has been synthesized in methanol with the concentrated sulfuric acid from the 3-location of diflunisal's carboxylic acid; The reaction of this compound with hyrazine-hydrate in ethanol medium resulted in 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylic acid hydrazide [SGK 20], original 2',4'-difluoro-4-hydroxybiphenyl-[(substimtearyl)memylene]-3 -carboxylic acid hydrazides [SGK 373-392], (SGK 373-392] have been synthesized as a result of the condensation of hydrazide v/ith substitute aldehydes in ethanol medium; and original 2 ^, ,4'-difluoro-4-hydrox3'biphenyl-3-carboxylic acid [2-substitutearyl-4- thiazolidone-3-yl] amides [SGK 393-412] have been synthesized by compounds [SGK 373-392] with thioglicolic; acid (mercaptoacetic acid) in toluene under Dean- Stark aparatus.. The purities of the synthesized compounds have been controlled with high pressure liquid chromatography and the correctness of the structures have been proved with elemental analysis, and FT-IR and ^-NMR spectral data.

The aldehydes used during the stage of producing [SGK 373-392] from [SGK 20] will be preferably chosen from the group comprising 3-bromobenzaldehyde, 2- chlorobenzaldehyde, 2-chloro-6-fluorobenzaldehyde, 4-cyanobenzaldehyde, 2,6- dichlorobenzaldehyde, 2,6-difluorobenzaldehyde, 3,4-dichlorobenzaldehyde, 2,2- difluoro-l,3-benzodioxol-5-carboxyaldehyde, 5-ethyl-2-furaldehyde, 5- ethylthiophene-2-carboxyaldehyd e, 5 -methylthiophene-2-carboxyaldehyde, 1 - naphthaldehyde, 2-naphthaldehyde, pyridine-2-carboxyaldehyde, pyridine-3- carboxyaldehyde, pyridine-4-carboxyaldehyde, 3-phenoxybenzaldehyde, thiophene- 2-carboxyaldehyde, 3-(trifluoromethyl)benzaldehyde and 4-

(trifluoromethyl)benzaldehyde.

Scheme 1- i : CH ₃ OH / H ₂ S0 ₄ ; ϋ : NH ₂ NH ₂ .H ₂ 0 ; Hi : Ar-CHO / EtOH ; iv : HS-CH2-COOH/ toluene.

Synthesis method of 2',4'-dinuoro-4-hydroxy-iV-(arylmethylidene)biphenyI- 3-carbohydrazide [SGK 373-392]:

Substitute aldehydes (0,005 mol) dissolved in ethanol is added on to 2',4'- Difluoro-4-hydroxy-biphenyl-3-c8iboxylic acid hydrazide [SGK 20] (0,005 mol) again dissolved in ethanol, and the mixture is refluxed for 2 hours, then the mixture is cooled and the solid matter which has precipitated is washed with water and dried. The product obtained and recrystallised twice from ethanol. Synthesis method off 2',4'-difluoiO-4-hydroxy-N-(2-aryl-4-oxo-ly3- thiazolidin-3-yl)biphenyl-3-carboxaniide [SGK 393-412] :

SGK 373-392 (0,0025 mol) is heated using Dean-Stark apparatus with thioglycolic acid in a dry toluene medium, and at the end of the reaction stage toluene is evaporated until dried. The medium is put into reaction until C0 ₂ output is completed with NaHC0 ₃ (5%) solution, the obtained matter is washed with distilled water and is purified with ethanol-water (50%) mixture.

The [SGK 373-392] compounds present in the hydrazide-hydrazone structure have been obtained as pure compounds with a yield of 78-95%. There is important proof showing the compounds within this series are formed. When the FT-IR spectrums of these compounds are examined, while the amide band belonging to the CONHN=CH- structure showed band at 1629-1647 cm ^"1 , hydrazone band belonging to the C=N group showed a band at 1583-1616 cm ^'1 . When 1H-NMR results are examined, and ^-NMR spectrums are inspected, peak has been observed in the - NH ₂ group arising from CONHNH ₂ belonging to diflunisal hydrazide, which somehow proves that our compounds are formed. The peak belonging to the azometine protons (-CH=N-) of [SGK 373-392] compounds within the structure of hydrazide-hydrazone, has been determined as a singlet as a result of the proton integration around approximately 8.47-9.11 ppm. When the ¹³ C-NMR spectrums of hydrazide-hydrazones were examined, the peak belonging to the carbonyl group was determined to be around 164.80-165.38 ppm

When the [SGK 393-412] FT-IR spectrums within the compounds of thiazolidone structures was examined, the band belonging to the carbonyl group which proves the thiazolidone ring has been observed to be approximately around 1676-1708 cm ^"1 . The ^-NMR findings of 4-Thiazolidones also support that compounds have been formed. The S-CH ₂ protons belonging to the thiazolidone ring of compounds have been found to have approximately 3.92-3.94 ppm between two protons; and it has been proved by S-CH-N protons, that the ring was formed with the observation of a singlet corresponding to a proton around 6.01 -6.78 ppm The invention set forward here described that the original 2',4'-difluoro-4- hydroxy-N-Carylmethylideneibiphenyl-S-carbohydrazides via diflunisal hydrazides are characterized in that, 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylic acid hydrazides were synthesized from the reaction with substitute aldehydes in an ethanol medium, and that original 2',4'-difluoro-4-hydroxy-N-(2-aryl-4-oxo-l,3- thiazolidine-3-yl)biphenyl-3-carboxamide was synthesized by heating of the 2',4'- difluoro-4-hydroxy-N-(arylmethylidene) biphenyl-3-carbohydrazide in a toluene medium using Dean-Stark apparatus and within the presence of thioglycolic acid.

The invention that has been s et forward here, actually consists of the synthesis of the below mentioned substances initially; however it cannot be limited with this and they comprise the compounds of

N'-[(3-bromophenyl)methylidene |-2',4'-difluoro-4-hydroxybiphenyl-3- carbohydrazide

-N'-[(2-chlorophenyl)methylidene:]-2 ^, ,4 ^, -difluoro-4-hydroxybiphenyl-3- carbohydrazide

- N'-[(2-chloro-6-fluorophenyl)m(;thylidene]-2',4'-difluoro-4- hydroxybiphenyl-3- carbohydrazide

- N'-[(4-cyanophenyl)methylidene]-2 ^l ,4'-difluoro-4-hydroxybiphenyl-3- carbohydrazide

- N'-[(2,6-dichlorophenyl)methylidene]-2',4'-difluoro-4-hydrox ybiphenyl-3- carbohydrazide

- N'-[(2,6-difluorophenyl)methyli(lene]-2',4'-difluoro-4-hydro xybiphenyl-3- carbohydrazide

- N'-[(3,4-dichlorophenyl)methylidene]-2',4'-difluoro-4-hydrox ybiphenyl-3- carbohydrazide

-N'-[(2,2-difluoro-l,3-benzodioxol-5-yl)methylidene]-2',4 ^, -difluoro-4- hydroxybiphenyl-3 -carbohydrazid e

- N'-[(5-ethylfuran-2-yl)methylidene]-2',4'-difluoro-4-hydroxy biphenyl-3- carbohydrazide

- N'-[(5-ethylthiophen-2-yl)methylidene]-2',4'-difluoro-4-hydr oxybiphenyl-3- carbohydrazide

- N'-[(5-memylthiophen-2-yl)metbylidene]-2',4'-difluoro-4-hydr oxybiphenyl-3- carbohydrazide

- 2',4'-difluoro-4-hydroxy-N-(naphthalen-l-yl-methylidene)biph enyl-3- carbohydrazide

-2',4'-difiuoro-4-hydroxy-N-(naphthalen-2-yl-methylidene)bip henyl-3- carbohydrazide -2',4'-difluoro-4-hydroxy-N-(pyridin-2-yl-methylidene)biphen yl-3-carbohydrazide

- 2',4'-difluoro-4-hydroxy-N-(pyridin-3-yl-n ethylidene)biphenyl-3-carbohydrazide -2',4'-difluoro-4-hydroxy-N-(pyridin-4-yl-methylidene)biphen yl-3-carbohydrazide -N'-[(3-phenoxyphenyl)methylid ne]-2',4'-difluoro-4-hydroxybiphenyl-3- carbohydrazide

-2^4'-difluoro-4-hydroxy-N'-[(thiophen-2-yl)methylidene]biph enyl-3-carbohydrazide

-2',4'-difluoro-4-hydroxy-N-{[3-(trifluoromethyl)phenyl]m ethylidene}biphenyl-3- carbohydrazide

-2',4'-difluoro-4-hydroxy-N- { [4-(trifluoromethyl)phenyl]methylidene} biphenyl-3 - carbohydrazide

-N-[2-(3-bromophenyl)-4-oxo-l,3-thiazolidin-3-yl]-2',4'-difl uoro-4- hydroxybiphenyl-3-carboxamide

- N-[2 2-cWorophenyl)-4-oxo-l,3-thiazolidin-3-yl]-2',4'-difluoro-4- hydroxybiphenyl-3 -carboxamide

- N-[2-(2-cWoro-6-fluorophenyl 4-oxo-l,3-tluazolidin-3-yl]-2 ^, ,4 ^, -difluoro-4- hydroxybiphenyl-3-carboxamide

- N-[2-(4-cyanophenyl)-4-oxo-l,3-thiazolidin-3-yl]-2',4'-diflu oro-4- hydroxybiphenyl-3-carboxamide

- N-[2-(2,6-dichlorophenyl)-4-ox( l,3-thiazolidine-3-yl]-2',4'-difluoro-4- hydroxybiphenyl-3-carboxamide

- N-[2-(2,6-difluorophenyl)-4-ox()-l,3-thiazolidin-3-yl]-2',4' -difluoro-4- hydroxybiphenyl-3-carboxamide

- N-[2-(3,4-dichlorophenyl)-4-ox()-l,3-thiazolidin-3-yl]-2',4' -difluoro-4- hydroxybiphenyl-3 -carboxamide

- N-[2-(2,2-difluoro-l,3-benzodioxol-5-yl)-4-oxo-l,3-^

4-hydroxybiphenyl-3-carboxarnide

- N-[2-(5-ethylfuran-2-yl)-4-oxo-l ,3-thiazolidin-3-yl]-2\4'-difluoro-4- hydroxybiphenyl-3-carboxamide

- N-[2-(5-e lthiophen-2-yl)-4-oxo-l,3-thiazolidin-3-yl]-2',4'-difluoro-4 - hydroxybiphenyl-3 -carboxamide

- N-[2-(5-methylthiophen-2-yl)-4-oxo-l,3-thiazolidine-3-yl]-2' ,4*-difluoro-4- hydroxybiphenyl-3-carboxamide

-N-[2-(naphthalen-l-yl)-4-oxo-l,3-thiazolidin-3-yl]-2',4 ^, -difluoro-4- hydroxybiphenyl-3-carboxamide

-N-[2-(naphthalen-2-yl)-4-oxo-l,3-thiazolidin-3-yl]-2',4' -difluoro-4- hydroxybiphenyl-3-carboxamide

-N-[2-(pyridin-2-yl)-4-oxo-l,3-11iiazolidin-3-yl]-2 ^, ,4 ^, -difluoro-4-hydroxybiphenyl-3- carboxamide

-N-[2-^yridin-3-yl)-4-oxo-l,3-thiazolidine-3-yl]-2',4 ^, -difluoro-4-hydroxybiphenyl-3- carboxamide

-N-[2-(pyridin-4-yl)-4-oxo-l,3-truazolidine-3-yl]-2',4'-difl uoro-4-hydroxybiphenyl-3- carboxamide -N-[2-(3-phenoxyphenyl)-4-oxo-l,3-1hiazolid-n-3-yl]-2',4'-di fluoro-4- hydroxybiphenyl-3 -carboxamide

-N-[2-(tWophen-2-yl)-4-oxo-l,3-thia2;olidin-3-yl]-2 ^, ,4'-difluoro-4-hydroxybiph( 3 -carboxamide

-N-{2-[(3-trifluoromethyl)phenylH^

hydroxybiphenyl-3-carboxamide

-N-{2-[(4-trifluorome l)pheny]]-4-oxo-l,3-thiazolidin-3-yl}-2',4 ^, -difluoro-4- hydroxybiphenyl-3 -carboxamide

Ar: 3-bromophenyl (SGK 373); 5-ethylfiiran-2-yl (SGK 381); 2-naphthyl (SGK 385); 4-pyridyl (SGK 388); 4-(trifluoromethyl)phenyl (SGK 392); 3 bromophenyl (SGK 393); 2,6-dichlorophenyl (SGK 397); 5-ethylfiiran-2-yI (SGK 401); 5-ethyIthiophen-2-yl (SGK 402); 5-methylthiophen-2-yl (SGK 403); 2

Ar: 3-bromophenyl (SGK 373); 3,4-dichlorophenyl (SGK 379); 5-ethylftiran-2-yl (SGK 381); 2-naphthyl (SGK 385); 2-pyridyl (SGK 386); 4- pyridyl (SGK 388); 3-(trifluoromethyI)phenyl (SGK 391); 3-bromophenyl (SGK 393); 2-chlorophenyl (SGK 394); 2-chloro-6-fluorophenyl (SGK 395); 4-cyanophenyl (SGK 396); 2,6-dichlorophenyl (SGK 397); 2,6-difluorophenyl (SGK 398); 3,4-dichlorophenyl (SGK 399); 5-ethylfuran-2-yl (SGK 401); 5-ethylthiophen-2-yl (SGK 402); 5- methylthiophen-2-yl (SGK 403); 2-naphthyl (SGK 405); 2- pyridyl (SGK 406); 3- pyridyl (SGK 407); 4- pyridyl (SGK 408); 3-phenoxyphenyl (SGK 409); thiophen-2-yl (SGK 410); 3-(trinuoromethyl)phenyl (SGK 411).