4191-73-5Relevant articles and documents
Method for preparing paraben
-
Paragraph 0033-0036, (2020/03/25)
The invention discloses a method for preparing paraben. The method comprises the following steps: adding p-hydroxybenzoic acid (Amol), an alcohol (Bmol) and a benzimidazole ionic liquid (Cmol) into adry three-neck flask, slowly heating, carrying out reflux reaction, and carrying out TLC monitoring until reaction is finished; carrying out reduced pressure distillation to remove a solvent, washingresidues with ethyl acetate, carrying out suction filtration, and carrying out spin-drying on an obtained filtrate to obtain paraben. The yield can reach 90% or above; an obtained filter cake is the benzimidazole ionic liquid and can be recycled; the ratio of A to B to C is 1: 5: (0.2-0.5). The method provided by the invention has the advantages that the catalyst can be recycled, green and environment-friendly effects are realized, the cost is reduced, and the method is an efficient method for synthesizing paraben.
Novel Benzothiazole Ionic Liquids as Catalysts for the Synthesis of Parabens
Liu, B.,Liu, Y.,Sun, J.,Yin, D.
, p. 1476 - 1483 (2020/10/02)
Abstract: A simple and green approach to the esterification of p-hydroxybenzoic acid and aliphatic alcohols to obtain parabens was developed. First, two novel benzothiazole ionic liquids [HBth]H2PW12O40 (IL1) and [HBth]H4PMo12O41 (IL2) were synthesized with benzothiazole and heteropolyacids as starting materials. The synthesized ionic liquids were characterized by FTIR spectroscopy, TGA, PXRD analysis, and SEM. The application of IL1 and IL2 as catalysts for the synthesis of parabens was explored. The results showed that the ILs had a high catalytic activity in the synthesis of parabens, and, at the same time, they could be easily recovered and reused five times without loss of activity.
A process for preparing Nepal jin zhi method (by machine translation)
-
Paragraph 0049; 0050; 0051; 0052; 0053; 0054; 0055, (2019/10/02)
The invention discloses a method for preparing Nepal jin zhi method: in a reaction container by adding of formula choline chloride (Amol) and methanesulfonic acid (Bmol), for 80 °C stirring to complete dissolution shall be low altogether [...]; cooling to room temperature, then added to the hydroxy benzoic acid of formula (Cmol) acrylic (Dmol), slow heating, reflux reaction, TLC monitoring until a reaction is finished (1 - 2 h); reaction liquid-cooled to the room temperature, precipitate solid, filtered, cake of a small amount of washing, get [...], a yield of 90% or more; recycling the filtrate to obtain low altogether [...]. Wherein A: B: C: D is 1: (1 - 4): 1: (1.1 - 1.5). The method of the invention short reaction time, efficiency is high, the catalyst can be recycled, environmental protection, and reducing the cost; to reduce the consumption of the stinging; low requirements on equipment, is an efficient method of synthesizing [...]. (by machine translation)
