Background[1]
N-hydroxymethylbenzamide is an organic intermediate that can be used in laboratory organic synthesis processes. It can be prepared from benzamide and formaldehyde in one step. There are reports in the literature that it can be used to prepare bacteriostatic UV absorbers.
Preparation[1]
To a solution of benzamide (70.0g, 0.58mol), add a 40% solution of formaldehyde (45.0g, 0.60mol) and potassium carbonate (2.00g, 14.5mmol) in water (70mL). This was heated on a water bath until a clear solution formed, and then crystallized. Recrystallization from dilute ethanol gave N-hydroxymethylbenzamide 6282-02-6 (79.4 g, 85%) as a crystalline solid, mp 104°C.
Apply[1]
CN201810571565.3 reported that N-hydroxymethylbenzamide can be used to synthesize 3,5-di-N-methylbenzamide-2,4-dihydroxybenzophenone. It has antibacterial and anti-UV dual functions. This bacteriostatic ultraviolet absorber has very good application prospects in the preparation of polymer materials.
The steps of the preparation method are as follows:
A. Friedel-Crafts acylation reaction
In an organic solvent of 150 to 300% by weight of reactants, in the presence of a catalyst of 10 to 30% by weight of reactants, 2,4-dihydroxybenzophenone and N-hydroxymethyl The benzamide reactant is subjected to Friedel-Crafts acylation reaction at a mass ratio of 1:0.8~1.2 at a temperature of 10~80°C for 1~7 days, and then centrifuged to obtain a precipitate;
B. Recrystallization
The precipitate obtained in step A is washed with distilled water until neutral, and then the washed precipitate is recrystallized in ethanol with a concentration of 30 to 50% by volume for 0.1 to 0.3 hours at room temperature, and then centrifuged and washed. Dry in a vacuum drying oven to obtain 3,5-di-N-methylbenzamide-2,4-dihydroxybenzophenone bacteriostatic ultraviolet absorber.
Main reference materials
[1] [Chinese invention] CN201810571565.3 A bacteriostatic ultraviolet absorber, its preparation method and application in polymers
