CN1147463C

CN1147463C - Process for preparing ethyl p-dimethylaminobenzoate

Info

Publication number: CN1147463C
Application number: CNB00112515XA
Authority: CN
Inventors: 胡国宜; 薛建伟; 胡亚东
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-09-06
Filing date: 2000-09-06
Publication date: 2004-04-28
Anticipated expiration: 2020-09-06
Also published as: CN1289764A

Abstract

The present invention discloses a preparation method of ethyl p-dimethylaminobenzoate which is prepared from ethyl p-aminobenzoate, methanol and formaldehyde as raw materials under the existence of raney nickel or palladium carbon as a catalyst. The preparation method orderly comprises the steps of material proportioning, stir, displacement, hydrogenation, separation, refrigeration, dehydration and drying. The present invention has the characteristics of simple and feasible technology, low cost of product preparation, high yield, high product purity, no problem of environmental pollution, etc.

Description

The preparation method of ESCAROL 507 ethyl ester

Technical field

The invention belongs to the chemical industry technical field, being specifically related to a kind of is raw material with parathesin, methyl alcohol, formaldehyde, in the presence of catalyzer, prepares a kind of industrialized preparing process of ESCAROL 507 ethyl ester through hydrotreatment.

Background technology

The ESCAROL 507 ethyl ester mainly is used as light trigger.It is believed that breath data-searching shows, at present in domestic other manufacturer that still finds no of China, manufacturer in the world also only is confined to a few countries such as the U.S., Japan and Britain, as UK Patent Application GB2233975A, application number is 9015680.3, name is called " preparation method of ESCAROL 507 alkyl ester or substituted alkyl ester ", a kind of " technology of preparation ESCAROL 507 ethyl ester " is disclosed, although its final product purity is higher, but its preparation technology, still exist complex process, preparation cost height, and problem such as environmental protection.

Summary of the invention

The object of the present invention is to provide that a kind of technology is simple, preparation cost is lower, substantially free of impurities and do not have the preparation method of environmental protection problem, to overcome the deficiencies in the prior art.

Realization the object of the invention has been taked following technical scheme, it is a raw material with parathesin (having another name called Benzocaine), methyl alcohol, formaldehyde still, in the presence of catalyzer, comprise batching successively, stir, vacuumize back inflated with nitrogen, hydrogenation, separation, cooling, remove raffinate and baking step with centrifuge.

And said batching step, be to be parathesin more than 99% with content: content is the methyl alcohol more than 99%: content is 37% formaldehyde: catalyzer=1: 3～4: 1～1.3: 0.08～0.1 (weight ratio), and weigh respectively and join work.

And said whipping step is that batching step is dropped into container in the lump and does and fully stir by weigh four kinds of materials of gained of said weight proportion.

And the hydrogenation reaction temperature of said hydrogenation step is 50 ℃～70 ℃, and pressure is 0.3～0.6MPa, and the reaction times is 10～14 hours.

And said separating step is to adopt filtration method to separate, and the mother liquor that the preceding one step hydrogenation reaction of order produced is separated into finished product stoste and catalyzer filter cake.

And said cooling step, be cooled in the temperature of preceding one step through separating the finished product stoste produced≤5 ℃ the time, promptly cooling step finishes.

And said baking step, its bake out temperature is 40 ℃～50 ℃, drying time is 6～8 hours.

The used catalyzer of the present invention is Raney nickel (Ni), or palladium carbon (Pd/C).And the present invention's Raney nickel (also claiming Raney's nickel) preferably.

The present invention has positive effect: by preparation method described above, prepared ESCAROL 507 ethyl ester final product, have that preparation technology is easy, preparation cost is lower, characteristics such as substantially free of impurities and no environmental protection problem, according to test, its content can reach＞and 99.8%, yield can reach 98%, and its water content then is≤0.1%.

Embodiment

One of embodiments of the invention are to be that the reactor of 1500 liters is a container with volume.And carry out according to following steps successively:

Batching.By the weight ratio that is provided in the technical scheme, the parathesin 200kg that weighs respectively and get content＞99%, the methyl alcohol 600kg of content＞99%, content are 37% formaldehyde 200kg, catalyst powder attitude Raney nickel 18kg.

Stir.With four kinds of materials that the first step proportioning is weighed, drop into stirring tank in the lump and stir.Till abundant stirring, churning time is about 1 hour.

Vacuumize the back inflated with nitrogen.Press usual method, the second step stirred materials is led injected equivalent volume reactor with heating or cooling water spacer.And inflated with nitrogen (N ₂) twice, promptly be evacuated to-0.09MPa, fill nitrogen again to 0.2MPa, be evacuated to again-0.09MPa, fill nitrogen again to 0.2MPa, so repeat twice.

Hydrogenation.And then to injecting hot water in the water spacer of reactor that has the material of third step after displacement,, in reactor, inject hydrogen (H simultaneously with 0.5MPa pressure to the material heating ₂).Because hydrogenation reaction is thermopositive reaction, thus should note the still interior reaction temperature, and regulated control by the temperature of in the water spacer, injecting water, make its temperature of reaction between 50 ℃～70 ℃.Reaction times is 12 hours.Entire reaction course adopts gas chromatograph or high speed liquid chromatography instrument to monitor.

Separate.With the mother liquor that preceding road hydrogenation reaction step is produced, import the filter paper pressure filter and filter, and the catalyzer Raney nickel powder that order is present in the mother liquor separates with finished product stoste.Catalyzer Raney nickel powder exists with the filter cake state, after treatment can reuse.

Cooling.The finished product stoste that to produce after separating is cooled to＜and 5 ℃, final product is then separated out with solid phase, promptly gets the compound of final product and raffinate.

Dehydration.Press usual method, the final product raffinate compound with preceding road cooling step is produced dries with centrifuge, and produces wet goods.

Oven dry.The wet goods that preceding road is produced are inserted in the Hotaircirculatingoven and are dried.Storing temperature is 40 ℃ ± 2 ℃, 6 hours time, treat that sample presentation detects its water content≤0.1%, and baking step finishes.

Thereafter, with the packing of fiber can plastic lining bag film, every barrel of 40kg, export trade can appear on the market.

Two of embodiments of the invention, the weight ratio that is provided in by technical scheme in when batching, parathesin 200kg, the methyl alcohol 600kg of content＞99%, the content of getting content＞99% of weighing respectively is 37% formaldehyde 200kg, contains the palladium catalyst carbon 2kg that the palladium amount is 3%-10%, and other step is as one of embodiment.

The used catalyzer of the present invention is the Raney nickel powder preferably, and also available palladium (Pd) amount that contains is the palladium carbon of 3%-10% (can by Russian, Taiwan import).And catalyzer Raney nickel powder can be added liquid phase sodium hydroxide (NaOH) and be produced after reaction by the al-ni alloy powder that contains (Ni) amount＞45%.There is confession in catalyzer Raney nickel powder market.

Of the present invention through the raffinate that centrifuge dehydration became, qualified discharge after recycling.There is not environmental issue in the present invention.

Claims

1, a kind of preparation method of ESCAROL 507 ethyl ester is characterized in that, it comprises batching successively, stirs, vacuumizes back inflated with nitrogen, hydrogenation, separation, cooling, removes raffinate and baking step with centrifuge;

And in the raw material weight proportioning of said batching step being the parathesin of content＞99%: the methyl alcohol of content＞99%: content is 37% formaldehyde: catalyzer=1: 3～4: 1～1.3: 0.08～0.1; Catalyzer is Raney nickel or palladium carbon;

And at said whipping step, be with batching step by weigh four kinds of materials of gained of said weight proportion, drop into container in the lump and do and fully stir;

And be 50 ℃～70 ℃ in the hydrogenation reaction temperature of said hydrogenation step, pressure is 0.3～0.6MPa, the reaction times is 10～14 hours;

And said separating step is to adopt filtration method and the mother liquor that makes preceding one hydrogenation reaction produce, is separated into finished product stoste and catalyzer filter cake;

And said cooling step, be treat the temperature of preceding one separating step through separating the finished product stoste produced be cooled to≤cooling step finishes 5 ℃ the time;

And the bake out temperature of said baking step is 40 ℃～50 ℃, and drying time is 6～8 hours.

2, the preparation method of ESCAROL 507 ethyl ester according to claim 1 is characterized in that, said catalyzer is a Raney nickel.