Unlock instant, AI-driven research and patent intelligence for your innovation.
Method for preparing p-aminobenzoic acid alkyl ester
What is Al technical title?
Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A technology of alkyl aminobenzoate and alkyl nitrobenzoate, which is applied in the field of preparation of alkyl p-aminobenzoate, can solve the problems of increased production cost, large environmental impact, and large odor, and avoid solvents Loss, environmental friendliness, high yield effect
Pending Publication Date: 2019-10-18
CHANGZHOU YONGHE FINE CHEM
View PDF5 Cites 0 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
[0004] These two types of methods all need to reclaim excessive solvents such as alkyl alcohol or toluene, which not only increases post-processing, but also inevitably causes losses during the recovery process, which increases production costs, especially for some medium carbon atoms (the number of carbon atoms is 4~8) Alkanols have a strong smell, and the recovery process has a great impact on the environment
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1）
[0015] The present embodiment is the preparation method of n-butyl p-aminobenzoate, specifically as follows:
[0016] ①Add 200g of n-butyl p-nitrobenzoate (0.9mol), 73.3g of n-butanol (0.99mol) and 167g of p-nitrobenzoic acid (1mol) into the esterification reaction device, and slowly drop them under stirring After adding 1.9g of concentrated sulfuric acid, raise the temperature to reflux (120±1°C), keep it warm for 12 hours, then raise the temperature to 128±1°C, and divide 17.8g of water.
[0017] After the reaction, cool to 35±1°C, neutralize to pH=7.5±0.1 with aqueous sodiumcarbonate solution, stand and separate layers to obtain 421 g of the lower organic relative n-butyl nitrobenzoate, with a yield of 99.1% and a purity of 99.26% (HPLC).
[0018] Wherein, the n-butyl p-nitrobenzoate of 200g is reserved as the solvent of the next batch of esterification reactions, and the n-butyl p-nitrobenzoate of the remaining 221g is used for the catalytic hydrogenation of the next ste...
Embodiment 2）
[0021] The present embodiment is the preparation method of isooctyl p-aminobenzoate, specifically as follows:
[0022] ①Add 200g of isooctyl p-nitrobenzoate (0.72mol), 128.7g of isooctyl alcohol (0.99mol), 167g of p-nitrobenzoic acid (1mol) and 8.4g of p-toluene into the esterification reaction device Sulfonic acid, stirred and heated to refluxdehydration (118-130°C), kept at reflux for 4-6 hours, no water came out, and a total of 18.2g of water was separated.
[0023] After the reaction, cool to 45±1°C, neutralize with aqueous sodium hydroxide solution to pH=7.5±0.1, stand and separate layers to obtain 476g of the lower organic phase nitrobenzoate isooctyl, the yield is 98.9%, the purity 99.38% (HPLC).
[0024] Wherein, 200g of isooctyl p-nitrobenzoate is reserved as a solvent for the next batch of esterification reactions, and the remaining 276g of isooctyl p-nitrobenzoate is used for catalytic hydrogenation in the next step.
[0025] ②Add 276g of isooctyl p-nitrobenzoate...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More
PUM
Login to View More
Abstract
The invention discloses a method for preparing p-aminobenzoic acidalkyl ester. The method comprises the following steps: performing an esterification reaction on p-nitrobenzoic acid and a corresponding alkylalcohol so as to obtain p-nitrobenzoic acidalkyl ester, and further performing catalytic hydrogenation, so as to obtain the p-aminobenzoic acid alkyl ester, wherein the solvent used in the esterification reaction is p-nitrobenzoic acid alkyl ester; the mole ratio of p-nitrobenzoic acid to the p-nitrobenzoic acid alkyl ester is (1:0.5)-(1:1); the alkyl alcohol is a C4-C8 alcohol; the moleratio of the p-nitrobenzoic acid to the alkyl alcohol is (1:0.98)-(1:1.1); the esterification reaction is implemented in the presence of the catalyst; and the catalyst is sulfuric acid or p-toluenesulfonic acid. The invention unexpectedly shows that an esterification reaction product, namely the p-aminobenzoic acid alkyl ester, can be used as a solvent of the esterification reaction, with the esterification reaction solvent, the process that an alcohol or benzene solvent needs to be recycled in a conventional method is avoided, not only is aftertreatment simple, but also solvent consumption is avoided, and the method is environment-friendly.
Description
technical field [0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a preparation method of alkyl p-aminobenzoate. Background technique [0002] At present, the preparation method of alkyl p-aminobenzoate is mainly to obtain alkyl p-nitrobenzoate through esterification reaction of p-nitrobenzoic acid and corresponding alkyl alcohol, and then obtain p-aminobenzene through catalytic hydrogenation. Alkylformate. [0003] At present, there are two main types of solvents used in the above-mentioned esterification reaction. One is to use the raw material alkyl alcohol as a solvent, that is, the alkyl alcohol is usually about 4 times the mole of p-nitrobenzoic acid; the other is toluene etc. as a water-carrying agent. [0004] These two types of methods all need to reclaim excessive solvents such as alkyl alcohol or toluene, which not only increases post-processing, but also inevitably causes losses during the recovery process, whi...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to View More 
Login to View More