Process for direct alpha-methylenation of ketones
A technology of methylene ketone and group, applied in the field of preparation of α-methylene ketone
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
example
[0037]
[0038] On the left side of this reaction scheme, an organic compound containing a carbonyl (acid functionality) and an amine functionality is shown. The tautomer on the right is its corresponding zwitterion.
[0039] It is intended in the context of the present invention that any organic compound having acid functionality and amine functionality includes zwitterions thereof.
[0040] In such compounds, the amino function may be any known amine group, especially primary or secondary amines. The acid functionality can be any known acid group, such as carboxylic, sulfonic or phosphonic acids. Preferred are carboxylic acid residues. For example, the catalyst may be a compound of general formula (II)
[0041]
[0042] where R 1 is H or a hydrocarbon residue which may be interrupted by one or more heteroatoms and / or one or more heteroatoms containing groups and / or may be substituted by one or more functional groups,
[0043] X is an acid function or a correspondi...
example 1
[0086] This example shows a comparison of the catalytic performance of different amino acid catalysts for the methylenation of acetophenone (30 mol% amino acid, 30 mol% HCl aq. , CH 2 O 4.2 equivalents, DMSO, 80°C, 5 hours)
[0087] Reactions were performed in a 25 mL round bottom flask equipped with a condenser and magnetic stirrer. Amino acid to be tested (1.2 mmol) and paraformaldehyde (0.505 g, 16.8 mmol) as catalysts were dissolved in DMSO (10 mL) and the mixture was stirred at room temperature. Aqueous hydrochloric acid (37 wt%) (99 μL, 1.2 mmol) was then added to the mixture, followed by acetophenone (0.481 g, 4 mmol). The reaction was then heated at 80 °C for 5 h with stirring. The progress of the reaction was monitored by gas chromatography by recovering a 500 μL sample from the reaction mixture and using 1,2-dichlorobenzene as an internal standard (internal calibration for reactants and products).
[0088] Table 1 shows substrate conversion (TR), productive rate ...
example 2
[0094] This example shows a comparison of the catalytic performance of the best candidates selected in Example 1 at higher temperatures (30 mol% amino acid, 30 mol% HCl aq. , CH 2 O 4.2 equivalents, DMSO, 100°C, 5 hours)
[0095] Reactions were performed in a 50 mL round bottom flask equipped with a condenser and magnetic stirrer. Amino acid to be tested (2.4 mmol) and paraformaldehyde (1.01 g, 33.6 mmol) as a catalyst were dissolved in DMSO (20 mL) and the mixture was stirred at room temperature. Aqueous hydrochloric acid (37 wt %) (198 μL, 2.4 mmol) was then added followed by acetophenone (0.962 g, 8 mmol). The reaction mixture was then heated at 100° C. with stirring until the optimum yield was reached (the product yield was observed to reach a maximum during the reaction).
[0096] The progress of the reaction was monitored by gas chromatography by recovering a 500 μL sample from the reaction mixture using 1,2-dichlorobenzene as an internal standard (internal calibratio...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More