Patent Grant
11987551
The present invention relates to novel styryl carboxylates for the treatment of immunological diseases, inflammation, obesity, hyperlipidaemia, hypertension, neurological diseases, and diabetes.
Metabolic syndrome, Insulin resistance syndrome or Syndrome X is a name for a group of risk factors that occur together and increase the risk for coronary artery disease, stroke, and type 2 diabetes. Metabolic syndrome is becoming more and more common globally specially in the United States. Researchers are not sure whether the syndrome is due to one single cause, but all the risks for the syndrome are related to obesity. The two most important risk factors for metabolic syndrome are: Extra weight around the middle and upper parts of the body (central obesity) and insulin resistance. The body uses insulin less effectively than normal. Insulin is needed to help control the amount of sugar in the body. As a result, blood sugar and fat levels rise. Other risk factors include Aging, Genes, Hormone changes, Lack of exercise. People who have metabolic syndrome often have two other problems that can either cause the condition or make it worse. Excess blood clotting, and increased levels of blood substances that are a sign of inflammation throughout the body.
Metabolic syndrome is affiliated with three or more of the following signs: Blood pressure equal to or higher than 130/85 mmHg, Fasting blood sugar (glucose) equal to or higher than 100 mg/dL, large waist circumference (length around the waist Men—40 inches or more and Women—35 inches or more, Low HDL cholesterol (Men—under 40 mg/dL Women—under 50 mg/dL) and Triglycerides equal to or higher than 150 mg/dL. In general, metabolic syndrome is a combination of Type 2 diabetes, obesity, hyperlipidemia and hypertension.
People with metabolic syndrome have an increased long-term risk for developing heart disease, type 2 diabetes, stroke, kidney disease, and poor blood supply to the legs. There is no one single treatment option available to treat metabolic syndrome. Current drugs that control blood glucose are usually not effective in lowering body weight, hypertension and cholesterol. Similarly, drugs that manage lipid levels may or may not have impact on other metabolic parameters. The present invention was aimed to develop new class of therapeutics derived, modified, and chemically synthesized from natural product which can combat multiple arms of metabolic syndrome. The invention also describes one such core group of molecules with synthesis scheme and biological data for diabetes, obesity, inflammation, hypertension and hyperlipidemia.
The compounds and compositions of the present invention are used to treat diseases associated with Inflammation, which include (but are not limited to) the following: Chron's Disease, Appendicitis, Bursitis, Colitis, Cystitis, Dermatitis, Epididymitis, Gingivitis, Meningitis, Myelitis, Nephritis, Neuritis, Pancreatitis, Periodontitis, Pharyngitis, Phlebitis, Prostatitis, Sinusitis, Tendonitis, Tonsillitis, Urethritis, Vasculitis, Vaginitis, Rheumatoid Arthritis, Osteoarthritis, Psoriatic Arthritis, Septic Arthritis, Chronic Inflammation, Asthma, Hepatitis, Laryngitis, Thyroiditis, Lymphangitis, Gout, Arteritis, Bronchitis, Acne Vulgaris, Pneumonia, Sarcoidosis, Endocarditis, Myocarditis, Pericarditis, Duodenitis, Esophagitis, Folliculitis, Anemia, Hypersensitivity, Chronic Obstructive Pulmonary Disease, Complex Regional Pain Syndrome, Rhinitis and Celiac Disease.
The compounds and compositions of the present invention are used to treat diseases associated with Metabolic Syndrome, which include (but are not limited to) the following: Obesity, Dyslipidemia, Hyperglycemia, Non Alcoholic Fatty Liver Disease, Polycystic Ovary Syndrome, Sleep Apnea, Hyperinsulinemia, Insulin Resistance, Glucose Intolerance, Hypertension, Acanthosis Nigricans, Psoriasis, Coronary Artery Disease, Cardiac Arrest, Congestive Heart Failure, Arrhythmia, Peripheral Artery Disease, Stroke, Ischemic Heart Disease, Lipodystrophy, Diabetes Mellitus Type 2, Kidney Failure, Low Levels of HDL and Chronic Inflammation.
The present invention relates to novel Styryl Carboxylate derivatives of the formula (I)
their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates, wherein R1, R2, R3, R4 and R5 represent substituents on ring A and R6, R7 and R8 along with X and Y represent substituents on ring B as indicated in formula (I).
The present invention also relates to a process for the preparation of the above said novel compounds, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates, novel intermediates and pharmaceutical compositions containing them. Tautomeric forms are isomeric forms which exists in a state of equilibrium capable of reacting according to either form. Stereoisomers include configurational isomers, such as cis- and trans double bonds, as well as optically active isomers having different spatial arrangements of their atoms. Polymorphs are molecules which can crystallize in two or more forms. Solvates are molecular or ionic complexes of molecules or ions of solvent with those of a solute. Analogs also include atoms of the same family of the Periodic Table, such as F, Cl, Br and I. Derivatives include compounds resulting from routine functionalizing of atoms, such as, derivatives found by protecting by carboxylation or esterification, respectively.
In an embodiment of the present invention, the groups represented as R1, R2, R3, R4 and R5 on ring A are predominantly hydrogen.
In an embodiment of the present invention, the group represented by R7 is a carbonyl group through which free amino group containing molecules can form condensates. R7 can also be selected from groups such as ethanedithiol and propanedithiol.
In an embodiment of the present invention, the styryl ring represented as ring A can contain one or multiple side chain substituents ranging from hydrogen, phenoxy, amino, sulphonyl, substituted, unsubstituted, straight chain or branched alkyls derivatives, halogens, and the like. This also defines the range of substituents accommodated by R1, R2, R3, R4 and R8.
In an embodiment of the present invention, the groups represented by R6 and R8 on ring B can be selected from hydrogen, Hydroxy, alkoxy and branched or unbranched alkyl derivatives.
In an embodiment of the present invention, the groups represented by X and Y on ring B can be selected from hydrogen or Halogens like fluorine, chlorine, bromine, and iodine.
Pharmaceutically acceptable salts forming part of this invention include base addition salts such as alkali metal salts like Li, Na, and K salts, alkaline earth metal salts like Ca and Mg salts, salts of organic bases such as lysine, arginine, guanidine, diethanolamine, chlorine and the like, ammonium or substituted ammonium salts. Salts may include acid addition salts which are sulphates, nitrates, phosphates, perchlorates, borates, hydrohalides, acetates, tartarates, maleates, citrates, succinates, palmoates, methanesulphonates, benzoates, ascorbates, glycerophosphates, ketoglutarates and the like. Pharmaceutically acceptable solvates may be hydrates or comprising other solvents of crystallization such as alcohols.
More preferably, the present innovation relates to novel Styryl Carboxylate compounds of formula (I),
their derivatives, their analogs, their tautomeric forms, their stereoisomers, their polymorphs, their pharmaceutically acceptable salts, their pharmaceutically acceptable solvates, novel intermediates and pharmaceutical compositions containing them, wherein, the groups represented as R6 and R8, in the ring B are selected from hydrogen and alkoxy derivatives. The group represented by R7 on ring B will be a carbonyl group which forms Schiff bases with compounds having a free amino group and forms thioketalization with compounds like ethanedithiol and propandithiol. The benzene ring represented as Ring A can contain substituents represented by R1, R2, R3, R4 and R5 that are selected from linear or branched, substituted or unsubstituted (C1 to C12) alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, hexyl, octyl, nonyl and the like; substituted or unsubstituted (C1-C12) alkoxy group such as methoxy, ethoxy, propoxy, butoxy and the like; hydroxyl group or extended chain through an alkyloxy ester or un-substituted or substituted aryloxy ester groups; amines, sulphonyl, halogens and the like. The groups represented by X and Y on ring B are preferentially selected from hydrogen and Halogens like fluorine, chlorine, bromine and iodine.
The formula of the useful compounds synthesized in this present are listed below.
The list also consists of the IUPAC names of the compounds given the table below—
Preferred salts for the compounds listed above are hydrochloride, hydrobromide, sodium, potassium or magnesium.
According to another feature of this present invention, there is provided a process for the preparation of the compound represented by the formula I, wherein all symbols are as defined as earlier, as shown in scheme(I):
The reaction of compound of general formula (1a) with thionyl chloride, where the groups R1, R2, R3, R4 and R5 of the compound (1a) have been defined earlier, to produce a compound of the general formula (1b) may be carried out in an inert atmosphere which may be maintained by using inert gases such as Nitrogen, Argon or Helium. Thionyl chloride is added drop wise to the compound (1a) which may be taken as such without any solvents. After addition of thionyl chloride, the reaction mixture is subjected to reflux. The reaction temperature may vary between 20° C. to 150° C., but more preferably between 60° C. to 90° C. The duration of the reaction may range from 1 to 24 hours, preferably between 4 to 6 hours. After refluxing the excess thionyl chloride is distilled off to obtain (1b).
The reaction of compound of general formula (1b) with a compound of general formula (2a) where the groups R6, R7, X and Y have been defined earlier may be carried out using a polar protic solvent like chloroform and in the presence of weak bases like DEA, TEA, Isopropylamine, pyridine, pipridine and the like, but more preferably with a base like TEA. The reaction temperature may range between 0 to 20° C., more preferably in the range of 5-10° C. The reaction time may range from 1 to 10 hours and following completion of the reaction, the product may be extracted from the reaction mixture by washing the organic phase with an aqueous solvent followed by precipitation using non polar solvents like butane, pentante, hexane, cyclohexane etc. to obtain compound of formula (3a).
The reaction of compound of general formula (3a) with an aliphatic or aromatic amines or amino acids, wherein the amino group reacts, is possible only when R7 is a keto functional group like (—CHO) or (C═O). This reaction may take place in the presence of any alcohol along with catalytic amounts of mineral acids such as sulphuric acid. The reaction temperature may vary from 0 to 100° C. preferably in the range of 50-70° C. and the reaction time may vary between 1 to 24 hours, preferably in the range of 4-7 hours. The schiff base or the imine thus formed may be precipitated or could be extracted after suitable workup procedures such as water quenching. The resultant molecule is the styryl carboxylate of general formula (4a) where the groups have been defined earlier.
The invention is explained in detail in the examples given below which are provided by way of illustration only and therefore should not be construed to limit the scope of the invention.
Cinnamic acid (50.0 g) was taken in a clean and dry three neck round bottom flask and thionyl chloride (175 ml) was added drop wise with constant stirring. The reaction mixture was refluxed at 70-80° C. for five hours. After reflux the excess thionyl chloride was distilled off. Hexane was added and distillation was performed again to remove any traces of thionyl chloride. The product was then transferred to an amberlite bottle stored. (Yield 53.0 g)
4 hydroxy benzaldehyde (14.69 g) was taken in a clean and dry two neck round bottom flask and chloroform (200 ml) was added with constant stirring. The reaction mixture was cooled to 10-15 and Nicotonyl chloride (20.0 g) was added drop wise. Stirring was continued for another 15 minutes and TEA (16.44 ml) was added drop wise and the reaction was allowed to stir for 4 hours. It was then transferred to a separating funnel and washed twice with water (2×250 ml). The chloroform layer was separated and further washed with 10% NaOH solution (2×250 ml) and then dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under vaccum. Hexane was then added to the concentrated chloroform layer and the solid formed was filtered and dried. (Yield 15.7 g)
Stage (ii) compound (2.5 g) was taken in a clean and dry round bottom flask and Methanol (25 ml) was added. The reaction mixture was cooled to 15 C and sodium acetate (2.5 g) was added. Hydroxylamine hydrochloride (1.25 g) dissolved in 10 ml of water was added drop wise to the reaction mixture with constant stirring. Stirring was continued for 4 hours at room temperature.
The reaction mixture was then transferred to a beaker containing 100 ml of water. The precipitated solid was filtered, washed with water and then followed by hexane and dried. (Yield 1.2 g)
The synthesized compound was confirmed by proton NMR.
7.25 (d, 1H), 7.61 (d, 1H), 6.67 (d, 1H), 6.64 (d, 1H), 8.17 (s, 1H), 1.28 (s, 1H), 6.674 (d, J=16.5, 1H), 7.929 (d, J=16.5, 1H), 7.28 (d, 1H), 7.24 (t, 1H), 7.23 (t, 1H), 7.46 (t, 1H), 7.45 (d, 1H)
Cinnamic acid (50.0 g) was taken in a clean and dry three neck round bottom flask and thionyl chloride (175 ml) was added drop wise with constant stirring. The reaction mixture was refluxed at 70-80° C. for five hours. After reflux the excess thionyl chloride was distilled off. Hexane was added and distillation was performed again to remove any traces of thionyl chloride. The product was then transferred to an amberlite bottle stored. (Yield 53.0 g)
Vanillin (22.8 g) was taken in a clean and dry round bottom flask and chloroform (200 ml) was added whilst stirring. The reaction mixture was cooled to 5-10° C. Cinnamoyl chloride (25.0 g) was added drop wise. Stirring was continued for another 15 minutes and TEA (20.55 ml) was added drop wise while stirring. The reaction was allowed to continue for 5 hours with constant stirring. The reaction mixture was then transferred to a 1 L beaker and washed twice with water (2×250 ml). The chloroform layer was separated and further washed with 10% NaOH solution (2×250 ml) and then dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under vacuum. Hexane was then added to the concentrated chloroform layer and the solid formed was filtered and dried. (Yield 16.2 g)
Cinnamoyl vanniline (5.7 g) was taken in a round bottom flask and methanol (50 ml) was added. The reaction mixture was cooled to 15° C. and sodium acetate (7.89 g) was added. Hydroxyl amine (2.8 g) was dissolved in (25 ml) of water and this was added drop wise to the reaction mixture under constant stirring. The reaction mixture was allowed to stir for 4 hours and then transferred into a beaker containing 100 ml of water. The precipitated solid was filtered, washed with water, followed by hexane and then dried. (Yield 2.8 g)
7.25 (d, 1H), 7.61 (d, 1H), 6.67 (d, 1H), 3.85 (s, 3H), 8.17 (s, 1H), 1.28 (s, 1H), 6.674 (d, J=16.5, 1H), 7.929 (d, J=16.5, 1H), 7.28 (d, 1H), 7.24 (t, 1H), 7.23 (t, 1H), 7.46 (t, 1H), 7.45 (d, 1H)
Cinnamic acid (50.0 g) was taken in a clean and dry three neck round bottom flask and thionyl chloride (175 ml) was added drop wise with constant stirring. The reaction mixture was refluxed at 70-80° C. for five hours. After reflux the excess thionyl chloride was distilled off. Hexane was added and distillation was performed again to remove any traces of thionyl chloride. The product was then transferred to an amberlite bottle and stored. (Yield 53.0 g)
Vanillin (22.8 g) was taken in a clean and dry round bottom flask and chloroform (200 ml) was added whilst stirring. The reaction mixture was cooled to 5-10° C. Cinnamoyl chloride (25.0 g) was added drop wise. Stirring was continued for another 15 minutes and TEA (20.55 ml) was added drop wise while stirring. The reaction was allowed to continue for 5 hours with constant stirring. The reaction mixture was then transferred to a 1 L beaker and washed twice with water (2×250 ml). The chloroform layer was separated and further washed with 10% NaOH solution (2×250 ml) and then dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under vacuum. Hexane was then added to the concentrated chloroform layer and the solid formed was filtered and dried. (Yield 16.2 g)
Cinnamoyl vanilline (3.0 g), Urea (0.64 g) and Ethylacetoacetate (2.56 ml) were taken in a clean and dry three neck round bottom flask and Methanol (50 ml) and Sulphuric acid (5 drops) were added. This reaction mixture was subjected to reflux at 60-80° C. for 5 hours. After reflux, the reaction mixture was transferred to a beaker containing 200 ml of water. The precipitated solid was filtered, washed with water and followed with hexane and then dried. (Yield 1.42 g) 5.61 (s, 1H), 5.53 (s, 1H), 6.51 (s, 1H), 6.83 (d, 2H), 4.21 (m, 2H), 1.26 (t, 3H), 2.23 (s, 3H), 3.91 (s, 3H), 6.8 (d, 1H, J=16.5), 7.9 (d, 1H, J=16.5), 7.40 (d, 2H), 7.25 (t, 1H,)
Cinnamic acid (50.0 g) was taken in a clean and dry three neck round bottom flask and thionyl chloride (175 ml) was added drop wise with constant stirring. The reaction mixture was refluxed at 70-80° C. for five hours. After reflux the excess thionyl chloride was distilled off. Hexane was added and distillation was performed again to remove any traces of thionyl chloride. The product was then transferred to an amberlite bottle stored. (Yield 53.0 g)
Vanillin (22.8 g) was taken in a clean and dry round bottom flask and chloroform (200 ml) was added whilst stirring. The reaction mixture was cooled to 5-10° C. Cinnamoyl chloride (25.0 g) was added drop wise. Stirring was continued for another 15 minutes and TEA (20.55 ml) was added drop wise while stirring. The reaction was allowed to continue for 5 hours with constant stirring. The reaction mixture was then transferred to a 1 L beaker and washed twice with water (2×250 ml). The chloroform layer was separated and further washed with 10% NaOH solution (2×250 ml) and then dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under vacuum. Hexane was then added to the concentrated chloroform layer and the solid formed was filtered and dried. (Yield 16.2 g)
Cinnamoyl vanillin (5.0 g) was taken in a two next round bottom flask along with urea (2.2 g). Toulene (25 ml) was added and stirred and catalytic amounts of Paratoulylsulphonic acid (0.1 g) was added. The reaction mixture was refluxed for 4 hours at 100-110° C. After reflux the solvent was removed by distillation and the product was washed with water and followed by hexane and then dried. (Yield 3.12 g)
NMR Assignment
7.10 (1H, d), 7.20 (1H, d), 7.10 (1H, s), 3.80 (3H, s), 8.15 (1H, s), 6.20 (1H, d, J=16.5 MHz), 7.71 (1H, d, J=16.5 MHz), 7.35 (1H, d, Aromatic)
Cinnamic acid (50.0 g) was taken in a clean and dry three neck round bottom flask and thionyl chloride (175 ml) was added drop wise with constant stirring. The reaction mixture was refluxed at 70-80° C. for five hours. After reflux the excess thionyl chloride was distilled off. Hexane was added and distillation was performed again to remove any traces of thionyl chloride. The product was then transferred to an amberlite bottle stored. (Yield 53.0 g)
Vanillin (22.8 g) was taken in a clean and dry round bottom flask and chloroform (200 ml) was added whilst stirring. The reaction mixture was cooled to 5-10° C. Cinnamoyl chloride (25.0 g) was added drop wise. Stirring was continued for another 15 minutes and TEA (20.55 ml) was added drop wise while stirring. The reaction was allowed to continue for 5 hours with constant stirring. The reaction mixture was then transferred to a 1 L beaker and washed twice with water (2×250 ml). The chloroform layer was separated and further washed with 10% NaOH solution (2×250 ml) and then dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under vacuum. Hexane was then added to the concentrated chloroform layer and the solid formed was filtered and dried. (Yield 16.2 g)
Cinnamoyl vanillin (1.5 g) was taken in a clean two neck round bottom flask and Ethanol (25 ml) was added with stirring. 3-Aminophenol (0.6 g) was added lot by lot with constant stirring. After completion of addition, 2 drops of sulphuric acid was added. The reaction mixture was refluxed for 4 hours at 75-80° C. The solid product formed was filtered and washed with Ethanol and followed by water and finally by hexane and dried. (Yield 0.89 g)
NMR Assignment
6.81 (1H, d), 7.15 (1H, d), 7.10 (1H, s), 3.91 (3H, s), 6.72 to 7.10 (Aromatic), 6.20 (1H, d, J=16.5 MHz), 7.71 (1H, d, J=16.5 MHz), 7.15 to 7.35 (Aromatic)
Cinnamic acid (50.0 g) was taken in a clean and dry three neck round bottom flask and thionyl chloride (175 ml) was added drop wise with constant stirring. The reaction mixture was refluxed at 70-80° C. for five hours. After reflux the excess thionyl chloride was distilled off. Hexane was added and distillation was performed again to remove any traces of thionyl chloride. The product was then transferred to an amberlite bottle stored. (Yield 53.0 g)
4-hydroxy benzaldehyde (14.69 g) was taken is a clean and dry two neck round bottom flask and Chloroform (200 ml) was added whilst stirring. The reaction mixture was cooled to 5-10° C. Nicotinyl chloride (20.0 g) was added drop wise and stirring was continued for 15 minutes. TEA (16.44 ml) was added drop wise and the reaction was allowed to stir for 4 hours. It was then transferred to a separating funnel and washed twice with water (2×250 ml). The chloroform layer was separated and further washed with 10% NaOH solution (2×250 ml) and then dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under vaccum. Hexane was then added to the concentrated chloroform layer and the solid formed was filtered and dried. (Yield 15.7 g)
Cinnamoyl 4-hydroxy benzaldehyde (1 g) was taken in a clean and dry round bottom flask and methanol (10 ml) was added. 2,4 Dinitrophenylhydrazine (0.00 g) was added slowly into the reaction mixture and methanol (20 ml) was added. The reaction mixture was allowed to stir for 3 hours at room temperature. The solid formed was then filtered and washed with water and followed by hexane. (Yield 0.85 g)
NMR Assignment
6.81 (1H, d), 7.15 (1H, d), 7.6 (1H, s), 7.12 (1H, d), 8.30 (1H, s), 5.0 (1H, s), 8.5 (1H, s), 8.21 (1H, d), 6.62 (1H, d), 6.20 (1H, d, J=16.5 MHz), 7.71 (1H, d, J=16.5 MHz), 7.15 to 7.35 (Aromatic)
Cinnamic acid (50.0 g) was taken in a clean and dry three neck round bottom flask and thionyl chloride (175 ml) was added drop wise with constant stirring. The reaction mixture was refluxed at 70-80° C. for five hours. After reflux the excess thionyl chloride was distilled off. Hexane was added and distillation was performed again to remove any traces of thionyl chloride. The product was then transferred to an amberlite bottle stored. (Yield 53.0 g)
4 hydroxy benzaldehyde (14.69 g) was taken in a clean and dry two neck round bottom flask and chloroform (200 ml) was added with constant stirring. The reaction mixture was cooled to 10-15 and Nicotonyl chloride (20.0 g) was added drop wise. Stirring was continued for another 15 minutes and TEA (16.44 ml) was added drop wise and the reaction was allowed to stir for 4 hours. It was then transferred to a separating funnel and washed twice with water (2×250 ml). The chloroform layer was separated and further washed with 10% NaOH solution (2×250 ml) and then dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under vaccum. Hexane was then added to the concentrated chloroform layer and the solid formed was filtered and dried. (Yield 15.7 g)
compound of step 2 (5 g) was taken in a clean and dry two neck round bottom flask and PTSA (3.8 g) was added. Urea (1.3 g) was then added and Toulene (50 ml) was added with stirring. The reaction mixture was refluxed for 5 hours at 100-110 and allowed to cool over night at room temperature. The precipitated compound was filtered, washed with water and followed by hexane and dried. (Yield 3.34 g)
NMR Assignment
7.10 to 7.60 (Aromatic), 8.20 (1H, s), 5.0 (2H, s), 6.20 (1H, d, J=16.5 MHz), 7.71 (1H, d, J=16.5 MHz), 7.15 to 7.35 (Aromatic)
Cinnamic acid (50.0 g) was taken in a clean and dry three neck round bottom flask and thionyl chloride (175 ml) was added drop wise with constant stirring. The reaction mixture was refluxed at 70-80° C. for five hours. After reflux the excess thionyl chloride was distilled off. Hexane was added and distillation was performed again to remove any traces of thionyl chloride. The product was then transferred to an amberlite bottle stored. (Yield 53.0 g)
4 hydroxy benzaldehyde (14.69 g) was taken in a clean and dry two neck round bottom flask and chloroform (200 ml) was added with constant stirring. The reaction mixture was cooled to 10-15 and Nicotonyl chloride (20.0 g) was added drop wise. Stirring was continued for another 15 minutes and TEA (16.44 ml) was added drop wise and the reaction was allowed to stir for 4 hours. It was then transferred to a separating funnel and washed twice with water (2×250 ml). The chloroform layer was separated and further washed with 10% NaOH solution (2×250 ml) and then dried with anhydrous sodium sulphate. The chloroform layer was then filtered and concentrated under vaccum. Hexane was then added to the concentrated chloroform layer and the solid formed was filtered and dried. (Yield 15.7 g)
Compound from step (ii) (6.0 g) was taken in a clean and dry two neck round bottom flask and Chloroform (60 ml) was added with stirring. 1,3 Dithiane (2.7 g) and catalytic amount of iodine (0.1 g) was added and the reaction mixture was allowed to stir at room temperature for 5 hours. It was then quenched with cold water and the organic layer was separated which was further washed with water. The chloroform layer was then concentrated and the solid obtained was filtered, washed with hexane and then dried. (Yield 7.0 g)
NMR Assignment
2.44 (4H, t,), 2.03 (2H, m), 4.5 (2H, s), 6.8-7.1 (Aromatic), 6.20 (1H, d, J=16.5 MHz), 7.71 (1H, d, J=16.5 MHz), 7.15-7.35 (Aromatic).
This application claims the benefit of and priority to U.S. Provisional Application No. 63/141,816 filed 26 Jan. 2021, which is incorporated herein by reference.
| Entry |
|---|
| Dyrager et al. (Bioorganic & Medicinal Chem., 2011, 19(8), 2659) teaches (Year: 2011). |
| Number | Date | Country | |
|---|---|---|---|
| 20220234987 A1 | Jul 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| 63141816 | Jan 2021 | US |
