Method for producing benzopyranone compound and novel intermediate used therein
The present invention relates to a method for preparing 2-(2,5-difluorophenyl)-3-carboxy-7-chloro-(4H)-4-benzopyranone represented by formula 1 below, a novel intermediate used therein, and a method for preparing the same. Specifically, an object of the present invention is to provide a novel preparation method, in which the compound of formula 1 below can be efficiently and economically synthesized and can be mass-produced in a high yield.
1 . A compound of formula 2 below:
2 . A compound of formula 3 below:
3 . A method for preparing the compound of formula 2 according to claim 1 , comprising reacting 4-chloro-2-hydroxybenzoic acid with 2,5-difluorobenzoyl chloride to obtain the compound of formula 2
4 . The method according to claim 3 , wherein a reaction is carried out at −20 to 0° C. in at least one reaction solvent selected from the group consisting of tetrahydrofuran (THF), ether, methyl tert-butyl ether (MTBE), dichloromethane (DCM), acetonitrile (ACN), ethyl ether, and dioxin in the presence of at least one base selected from the group consisting of pyridine, triethylamine (TEA), diisopropylethylamine (DIPEA), dimethylaminopyridine (DMAP), potassium hydroxide, potassium carbonate, sodium acetate, lutidine, sodium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and cesium carbonate.
5 . The method for preparing the compound of formula 3 according to claim 2 , comprising reacting a compound of formula 2 below with oxalyl chloride to obtain the compound of formula 3
6 . The method according to claim 5 , wherein a reaction is carried out at room temperature in at least one reaction solvent selected from the group consisting of dichloromethane (DCM) and dimethylformamide (DMF).
7 . A method for preparing a compound of formula 1, comprising
(i) reacting the compound of formula 3 of claim 2 with a compound of formula 4 below to obtain a compound of formula 5 below; and
(ii) treating a compound of formula 5 below with an acid to obtain the compound of formula 1 below
8 . The method according to claim 7 , wherein in step (i), the reaction mixture obtained after reacting the compound of formula 3 with the compound of formula 4 is adjusted to pH 7 or less.
9 . The method according to claim 7 , wherein step (i) is carried out in at least one reaction solvent selected from the group consisting of toluene, tetrahydrofuran (THF), and dichloromethane (DCM) in the presence of at least one base selected from the group consisting of N,O-bis(trimethylsilyl) acetamide, triethylamine (TEA), and diisopropylethylamine (DIPEA).
10 . The method according to claim 7 , wherein step (ii) is carried out in at least one reaction solvent selected from the group consisting of ethyl acetate (EA), methanol, isopropyl alcohol (i-PrOH), and methyl tert-butyl ether (MTBE), and the acid is hydrochloric acid or trifluoroacetic acid.
11 . The method according to claim 7 , further comprising reacting a compound of formula 2 below with oxalyl chloride to obtain the compound of formula 3
12 . The method according to claim 11 , further comprising reacting 4-chloro-2-hydroxybenzoic acid with 2,5-difluorobenzoyl chloride to obtain the compound of formula 2.
13 . A method for preparing a compound of formula 1, comprising
reacting 4-chloro-2-hydroxybenzoic acid with 2,5-difluorobenzoyl chloride to obtain a compound of formula 2 below;
reacting the compound of formula 2 of claim 1 with oxalyl chloride to obtain a compound of formula 3 below;
reacting a compound of formula 3 below with a compound of formula 4 below to obtain a compound of formula 5 below; and
treating a compound of formula 5 below with an acid to obtain a compound of formula 1 below.
14 . A method for preparing a form IV crystal of a compound of formula 1, comprising adding the compound of formula 1 below to methyl isobutyl ketone (MIBK) to obtain the form IV crystal of the compound of formula 1
wherein the form IV crystal exhibits characteristic peaks at four or more diffraction angles 2θ±0.2° selected from the group consisting of 11.3, 14.7, 14.9, 16.9, 17.2, 22.5, and 25.7.
15 . A method for preparing a form IV crystal of a compound of formula 1, comprising
reacting 4-chloro-2-hydroxybenzoic acid with 2,5-difluorobenzoyl chloride to obtain the compound of formula 2 of claim 1 ;
reacting a compound of formula 2 below with oxalyl chloride to obtain a compound of formula 3 below;
reacting a compound of formula 3 below with a compound of formula 4 below to obtain a compound of formula 5 below;
treating a compound of formula 5 below with an acid to obtain a compound of formula 1 below; and
adding a compound of formula 1 below to methyl isobutyl ketone (MIBK) to obtain a form IV crystal of a compound of formula 1
wherein the form IV crystal exhibits characteristic peaks at four or more diffraction angles 2θ±0.2° selected from the group consisting of 11.3, 14.7, 14.9, 16.9, 17.2, 22.5, and 25.7.
16 . The method according to claim 14 , wherein a temperature at which the compound of formula 1 is added to the methyl isobutyl ketone (MIBK) is 15 to 25° C.