- Preparation method of piogelimide
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The invention provides a preparation method of piogelimide, which comprises the following steps: by using 4-[2- (5-ethyl-2-pyridyl)ethyoxyl]nitrobenzene as a starting material, methanol as a solvent and Raney Ni as a catalyst, carrying out catalytic hydrogenation, carrying out pressure filtration on the reaction solution into hydrobromic acid to carry out acidification reaction, and adding cuprousoxide, methyl acrylate and acetone into the system; dropwise adding a sodium nitrite solution, drying the organic solvent by distillation under reduced pressure after the reaction is finished, addingammonia water, alkalifying the solution by using liquid caustic soda, and extracting the product by using ethyl acetate; and adding thiourea and sodium acetate into the ethyl acetate solution, performing heating reflux until the reaction is finished, cooling the reaction product, adding water, spin-drying the reaction product, and refining the product by using DMF to obtain a piogelimide finishedproduct. According to the method, the yield and purity of the product can be effectively improved, the raw material cost is greatly reduced, the production operation is simplified, the production efficiency is improved, and the influence on the environment is greatly reduced.
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- A PROCESS FOR THE PREPARATION OF 4-[2-(5-ETHYL-2-PYRIDYL)ETHOXY]NITROBENZENE AND PIOGLITAZONE
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A process for the preparation of 4-[2-(5-ethyl-2-pyridyi)ethoxy]nitrobenzene is described, which comprises the step of reacting 2-(5-ethyl-2-pyridyl)ethanol with 1-fluoro-4-nitrobenzene in acetone in the presence of an alkali metal hydroxide. The intermediate 4-[2-(5-ethyl-2-pyridyI)ethoxy]nitrobenzene is used for the preparation of pioglitazone.
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Page/Page column 7
(2009/12/05)
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- PROCESS FOR THE PREPARATION OF THIAZOLIDINE DERIVATIVES
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The present invention relates to an industrially advantageous process for the preparation of thiazolidine derivatives, such as pioglitazone of formula I and its pharmaceutically acceptable salts.This invention also provides novel synthetic intermediates useful in the process for the preparation of pioglitazone.
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Page/Page column 16
(2008/12/06)
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- AN IMPROVED PROCESS FOR THE PRODUCTION OF DERIVATIVES OF THIOZOLIDINEDIONES AND THEIR PRECURSORS
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The invention provides a process for preparing derivatives of thiozolidinediones and their precursors comprising, (a) reacting a compound of general formula I wherein R1, R2 and R3 may be same or different and represent H, alkyl or alkoxy with C varying from 1 to 6, halogens, mono or di-substituted alkyl and aryl amines, and M represents hydrogen (H) or alkali metal selected from Na, K or Li with a compound of formula II, wherein R4 has the same meaning as R1 or R2 or R3 and X is halogen in presence or absence of solvent(s) under effective conditions to produce nitro ethers of general formula III, where in R1 to R4 has the same meaning as given above, provided when M is H and not its alkali metal salt, an alkali metal salt such as hydroxide or carbonate is required to be added while conducting the said reaction, (b) subjecting the said nitro ethers, with or without isolation, to Raney nickel-catalyzed reduction under conditions effective to produce corresponding nitro aniline ethers (c) coupling the said aniline ether with acrylates under Meerwein arylation conditions in presence of hydrobromic acid to produce α bromo substituted carboxylic acid derivatives followed by subjecting to solvent extractive purification (d) cyclising the purified derivative of α bromo substituted carboxylic acid as obtained in step (c) with thiourea to yield 2-imino -4-thiazolidinones then (e) hydrolyzing the said 2-imino-4-thiazolidinones to produce 2, 4-thiazolidinones and converting the same to its hydrochloride salts as white crystalline solids known to exhibit antidiabetic activity, by conventional methods.
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Page/Page column 24; 25
(2010/10/20)
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- INTERMEDIATE COMPOUND WHICH IS USED FOR THE PREPARATION OF PIOGLITAZONE
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The present invention relates to a novel compound of formula (IV) which is an intermediate that can be used for the preparation of pioglitazone. It also relates to a method of obtaining the novel compound (IV) starting from the natural product L-tyrosine, in which the amino group is protected in the form of aromatic imino group, and a method of obtaining pioglitazone from the said intermediate.
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- PROCESSES FOR MAKING PIOGLITAZONE AND COMPOUNDS OF THE PROCESSES
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Pioglitazone can be made via a Darzens Condensation reaction in an industrially useful process.
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Page/Page column 20-21
(2008/06/13)
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- PROCESS FOR THE PREPARATION OF 5-[[4-[2-(5-ETHYL-2-PYRIDINYL)ETHOXY]PHENYL] METHYL]-2,4-THIAZOLIDINEDIONE
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A process for the preparation of 5-[[4-[2-(5-ethyl-2-pyridinyl)ethoxy]phenyl]methyl]-2,4-thiazolidinedione (formula 1) comprising a. reacting diazonium salt of 4-[2-(5-Ethyl-2-pyridyl) ethoxy] amino- benzene, compound of formula 2, with acrylamide, aqueous HX (wherein X is Br or Cl), under meerwein arylation conditions to yield compound of formula 3; b. condensing compound of formula 3 with thiourea to obtain compound of formula 4; and c. converting compound of formula 4 to compound of formula 1.
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- Studies on antidiabetic agents. Synthesis and hypoglycemic activity of 5-[4-(pyridylalkoxy)benzyl]-2,4-thiazolidinediones
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The synthesis of a series of 5-[4-(pyridylalkoxy)benzyl]-2,4-thiazolidinediones is described. These compounds were evaluated for hypoglycemic and hypolipidemic activities in genetically obese and diabetic mice, yellow KK. 2-(2-Pyridyl)alkoxy derivatives were found to have much better hypoglycemic and hypolipidemic activities than 2-(3-pyridyl)- and 2-(4-pyridyl)alkoxy derivatives or even the previously reported compound, ciglitazone. The introduction of a hydroxyl group at the 2-position of the ethoxy chain potentiated the activities. Among the potent compounds, pioglitazone (AD-4833) was selected as a candidate compound.
- Sohda,Momose,Meguro,Kawamatsu,Sugiyama,Ikeda
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- Thiazolidinedione derivatives, useful as antidiabetic agents
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Thiazolidinedione derivatives of the formula: STR1 and pharmacologically acceptable salts thereof are novel compounds, which exhibit in mammals blood sugar- and lipid-lowering activity, and are of value as a therapeutic agent for treatment of diabetes and hyperlipemia.
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