A kind of preparation method of minodronic acid
A technology of minodronic acid and acetic acid, applied in chemical instruments and methods, compounds of group 5/15 elements of the periodic table, organic chemistry, etc., can solve the problems of difficult removal and low yield, and reduce the generation of impurities , improved yield, good effect of atom economy
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0035] Example 1: Synthesis of 2-(imidazo[1,2-a]pyridin-3-yl) ethyl acetate
[0036]Dissolve 23.5g (250mmol) of 2-aminopyridine in 100mL of absolute ethanol, add 35.4g of triethylamine and 2.4g of copper trifluoromethanesulfonate to the solution, and add dropwise 47.3 g of trifluoromethanesulfonate dissolved in 100mL of absolute ethanol to the solution while stirring. g of ethyl 4-chloroacetoacetate, heated to 55-60°C, reacted for 4-5 hours, TLC (developer: chloroform: methanol = 2:1) monitored the reaction solution until the 2-aminopyridine spots disappeared, and added 1% citric acid solution to the pH of the solution is 7.6, and the insolubles are removed by filtration, the filtrate is extracted with ethyl acetate, the organic layer is collected, dried and filtered, concentrated to give 47.4 g of light yellow viscous liquid, yield 92.8% ( Calculated as 2-aminopyridine), the purity is 97.57%, and the impurity 2-(imidazo[1,2-a]pyridin-2-yl)ethyl acetate is 0.43% (HPLC normaliz...
Embodiment 2
[0037] Example 2: Synthesis of 2-(imidazo[1,2-a]pyridin-3-yl) ethyl acetate
[0038] Dissolve 23.5g (250mmol) 2-aminopyridine with 100mL absolute ethanol, add 35.4g triethylamine, 2.4g copper trifluoroacetate in the solution, under stirring, add dropwise 49.5g 4 -Ethyl chloroacetoacetate, heated to 55-60°C, reacted for 4-5 hours, TLC (developing agent: chloroform:methanol=2:1) monitored the reaction solution until the 2-aminopyridine spots disappeared, and added 1% citric acid solution until the pH of the solution was 7.7, filtered to remove insoluble matter, the filtrate was extracted with ethyl acetate, the organic layer was collected, dried and filtered, and concentrated to obtain 47.0 g of a light yellow solid with a yield of 92.1%, a purity of 97.60%, and impurities 2-(imidazo[1,2-a]pyridin-2-yl)ethyl acetate 0.40% (HPLC normalization method).
Embodiment 3
[0039] Example 3: Synthesis of 2-(imidazo[1,2-a]pyridin-3-yl) ethyl acetate
[0040] Dissolve 23.5g (250mmol) 2-aminopyridine in 100mL of absolute ethanol, add 37.9g of triethylamine and 2.8g of copper acetate to the solution, and add dropwise 51.5g of 4-chloropyridine dissolved in 100mL of absolute ethanol under stirring. Ethyl acetoacetate, heated to maintain the temperature at 55-60°C, reacted for 4-5 hours, TLC (developing agent: chloroform: methanol = 2:1) monitored the reaction solution until the 2-aminopyridine spots disappeared, and added 1% to the solution citric acid solution until the pH of the solution was 7.7, filtered to remove insoluble matter, the filtrate was extracted with ethyl acetate, the organic layer was collected, dried and filtered, concentrated to give 45.7 g of light yellow viscous liquid, yield 89.7%, purity 95.87 %, impurity 2-(imidazo[1,2-a]pyridin-2-yl) ethyl acetate 0.55% (HPLC normalization method)
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More 


