- Preparation method of epalrestat
-
The invention relates to the technical field of medicines, in particular to a preparation method of epalrestat. The preparation method provided by the invention comprises the steps of mixing 3-carboxymethyl rhodanine, alpha-methylcinnamyl aldehyde, a catalyst and water, and sequentially carrying out condensation reaction and acid neutralization to obtain an epalrestat crude product, wherein the catalyst comprises a basic catalyst and a phase transfer catalyst; and mixing the epalrestat crude product with an alcohol organic solvent, and recrystallizing to obtain the epalrestat. The preparation method adopts water as a reaction solvent, and is safe and environment-friendly; the existing three procedures such as crude product preparation, acidification dissociation and recrystallization are simplified into two procedures such as crude product preparation and recrystallization, and the two procedures such as crude product preparation and acidification dissociation are combined into one, so that the procedures are simplified; and an alcohol organic solvent is adopted for recrystallization, so that recycling is facilitated.
- -
-
Paragraph 0047-0070
(2021/10/11)
-
- New epalrestat crystal form as well as preparation method and application thereof
-
The invention belongs to the technical field of medicines, and provides a novel epalrestat crystal form as well as a preparation method and application thereof. The X-ray powder diffraction pattern of the epalrestat new crystal form has characteristic diffraction peaks when the diffraction angles 2 theta are 6.39 +/-0.2 degrees, 7.57 +/-0.2 degrees, 12.69 +/-0.2 degrees, 14.67 +/-0.2 degrees, 15.04 +/-0.2 degrees, 21.79 +/-0.2 degrees, 24.36 +/-0.2 degrees, 25.59 +/-0.2 degrees, 27.30 +/-0.2 degrees and 31.48 +/-0.2 degrees. The epalrestat novel crystal form has excellent dissolution performance and water solubility, and the bioavailability of the epalrestat novel crystal form is improved; moreover, the epalrestat new crystal form has excellent flowability, the angle of repose can reach 26 degrees or below, the compression coefficient is smaller than 10%, the Hausner ratio is 1.00-1.11, and the epalrestat new crystal form is suitable for being used as a raw material medicine for production of prodrugs or pharmaceutical preparations of the epalrestat new crystal form.
- -
-
Paragraph 0079-0081; 0103-0114
(2021/11/19)
-
- PROCESS FOR PREPARING EPALRESTAT
-
PROBLEM TO BE SOLVED: To provide processes for preparing and purifying 2-((Z)-5-((E)-2-methyl-3-phenyl-allylidene)-4-oxo-2-thioxo-thiazolidin-3-yl) acetic acid (epalrestat). SOLUTION: Provided are processes for preparing and purifying epalrestat represented by the following formula (I), comprising the steps of: reacting rhodanine-3-acetic acid with (E)-2-methyl-3-phenyl-acryl-aldehyde in the presence of an ammonium salt(s) of an organic acid such as citric acid and DMF-containing solvent(s); isolating the produced epalrestat DMF solvate and drying it; suspending said epalrestat DMF solvate in ethanol; and further isolating the generated epalrestat crystal and drying it. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
- -
-
Paragraph 0058
(2017/08/08)
-
- STRUCTURAL ELUCIDATION OF EPALRESTAT(ONO-2235), A POTENT ALDOSE REDUCTASE INHIBITOR, AND ISOMERIZATION OF ITS DOUBLE BONDS
-
The structure of epalrestat (ONO-2235) is revised by X-ray single crystal analysis.The structures of the photoisomers are proposed on the basis of NMR and UV spectroscopic evidences.
- Ishida, Toshimasa,In, Yasuko,Inoue, Masatoshi,Ueno, Yoko,Tanaka, Chiaki,Hamanaka, Nobuyuki
-
p. 959 - 962
(2007/10/02)
-
