JPS60209552A - Production of 4,4-bis(carbalkoxymethylenamino) diphenylmethane - Google Patents

Abstract

PURPOSE:The reaction between methylenedianiline and monochloroacetic ester is effected in the presence of an acid acceptor to enable the production of the titled compound which is used as a starting substance for heat-resistant resins in no need of complicated and sophisticated purification process. CONSTITUTION:The reaction of methylenedianiline of formula I with monochloroacetic ester of formula II (R is 1-3C lower alkyl) is carried out in a methanol solvent using a weak base compound of alkali metal such as sodium carbonate or sodium bicarbonate as an acid acceptor at 50-70 deg.C in an inert gas atmosphere for about 5hr to give the objective compound of formula III. The acid acceptor is used in an amount of 1-2 equivalents to the compound of formula I and solvent, 3-4 times the weight of the compound of formula I . The ratio of the compound of formula II/that of formula I is at least 1 equivalent, preferably 1-2 equivalents.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is widely used in the paint field, and has unique functions as an important synthetic raw material for heat-resistant resins, etc.
i. (+'-bis(carbalkoxymethyleneamino)diphenylmethane)'1-

Conventionally, as a method for synthesizing arylene-N,N-diglycine esters, there has been proposed a method for synthesizing arylene-N,N-diglycine esters.
1. It is known that it can be obtained by reacting aromatic diamine and monochloroacetate in the presence of a hydrogen chloride acceptor such as sodium acetate, as described in Publication No. 5.・Ru.

However, as a result of repeated trials by the present inventors according to the above embodiment, it was found that the method had the following drawbacks and was not necessarily satisfactory. (Comparative Example 2) ■Water washing (here)
ql), the reactants solidify and the viscosity becomes high (candy state)
Therefore, sodium chloride produced as a by-product cannot be sufficiently dissolved and removed.Also, it is difficult to transfer the liquid and take out the crystals.

■ The wet crystals obtained by ITI separation (hereinafter referred to as 111i) contain the raw aromatic diamine and the sub/A:. It contains a considerable amount of substances and needs to be recrystallized. In addition, since the crystals are colored at °C, they must be decolored by treatment with activated carbon or the like.

■ Due to the above reasons, the raccoon process is complicated and long.

■ The yield was extremely poor at 201%.

Therefore, the inventors of the present invention have carefully considered the problems and carried out various investigations, and have found an improved technology that completely solves these drawbacks and is industrially superior, and has arrived at the present invention. did.

That is, the present invention is characterized in that: J) methylene dianiline and monochloroacetic ester are reacted in a methanol solvent using a weakly basic compound of an alkali metal as a dehydrochlorination agent. - A method for producing bis(carbalkoxymethyleneamino)diphenylmethane.

2) The method according to claim 1, wherein the dehydrochlorination agent is sodium carbonate or sodium bicarbonate.

It is.

The method of the present invention proceeds according to the following reaction formula.

Methylene dianiline (, i3 Monochloroacetate (II) 4,4'-bis(carbalkoxymethyleneamino)diphenylmethane (III) Where, R = lower alkyl group of C3 0 As a reaction solvent in the present invention methanol is applied. When methanol is used, the contents will not solidify during washing with water, making it easier to transfer the liquid and take out the crystals.

Furthermore, methanol is a good solvent because of the original II (
I) and by-products are easily dissolved in methanol, and the target product dl
This is because since l) is difficult to dissolve, impurities that cause solidification can be removed by filtration. On the other hand, aromatic hydrocarbons such as water and toluene do not have the above advantages and are not suitable.

(Comparative Example 3) The amount of the solvent methanol used is usually at least 2 times or more, preferably 3 to 4 times the weight of the raw material (I). In particular, the raw material (I) and the target product (III) are solid,
In order to smoothly proceed with solid-liquid operations including industrial upper limb liquid transfer and reactions, it is selected from a range that can maintain an appropriate slurry concentration.

As the dehydrochlorination agent in the present invention, a weakly basic compound of an alkali metal, ie, a weakly basic compound consisting of an alkali metal and a weak acid, is used. For example, sodium carbonate, potassium carbonate; zitorium hydrogen carbonate, potassium hydrogen carbonate;
Examples include sodium acetate and potassium acetate. Among these, sodium carbonate and hydrogen carbonate are particularly effective.7. ). When using sodium carbonate or sodium bicarbonate, the ll obtained by directly drying the wet crystals
The material (III) has high purity (no coloration at all
It is possible to omit all the advanced purification steps such as recrystallization and activated carbon treatment, as in the Toho method.

On the other hand, simple basic compounds such as urotropin and sodium hydroxide cannot affect the target compound (11,1) and are not suitable. (Comparative Example I) The amount of the dehydrochlorination agent used is at least 1 to 1 times as much as the raw material (1), preferably 1 to 2 times as much. Note that the dehydrochlorination agent used in excess is removed by water washing in the post-treatment step.

Usually, the charging ratio of raw material (■) / raw material (I) is at least 1
About twice the equivalent amount, preferably 1 to 2 times the equivalent amount, is used.

In addition, the reaction temperature is selected to be 50 to 7°C (reflux temperature), and if this is low, the reaction rate will be slow. The reaction is carried out at 5° C. for about 5 hours under an inert gas atmosphere.

Thus, the crude liquid (slurry liquid) obtained in this reaction can be easily purified through the cylinder wall lf post-treatment step.

An example is shown below.

First, the crude liquid is cooled to room temperature and then filtered, and the r' liquid (solvent) is separately collected and recycled to the reaction A1.

Add 2 to 4 times the volume of water (water washing) to the separated crude crystals, and wash at room temperature for about 0 minutes (after 115 cases).
Fi filtration 1l = i liquid is removed. Here, salts with alkali metals produced as by-products due to the reaction should be dissolved and removed.

The wet crystals are then dried at ℃ according to a conventional method to obtain the target GI.
A purified product (white solid) of I) can be obtained.

Furthermore, it is possible to purify to a higher degree by using methanol old crystals or rinsing according to the packaging.

Next, the method of the present invention will be explained in more detail by giving Examples and Comparative Examples. In addition, the object (III) is IR, N
Identification was made using BR, melting point, and elemental analysis.

Example] In a flask maintained under a nitrogen gas atmosphere, 20.7 g (o, + 5 mol) of methylethyldianiline (I), 5.2 g (+1 mol) of methyl monochloroacetate (J)
．． fi 0 mol), sodium carbonate 2 tE', 2
g (0,25 mol) and methanol], (19,4 g
was supplied. The mixture was heated to reflux at 65-70° C. for 5 hours with 1a7 stirring.

Next, the obtained reaction phase liquid was cooled and filtered to remove the solvent. Add 100 m, e of water to the crude crystals and incubate for 30 m at room temperature.
After stirring for 1 minute, the mixture was filtered for 11 minutes, and liquid f was removed.

Next, the wet crystals were vacuum dried to give pure white 4,4'-bis(
carbalkoxymethyleneamino) diphenylmethane (
(2): 48.59 (0.0jJ 0 mol) was obtained.

(Purity 1189, yield 6110%) Example 2 Carbonic acid was used as a dehydrochlorination agent) l) Same as Example 1 except that 4', I6g (CJ, '50 mol) of sodium hydrogen carbonate was used instead of rum. When processed in the same way, pure white objects (Ill) ``3], Fl y (o,
o+) 1 mol) was obtained. (Purity: 1985, yield: 6
Section 04) Comparative Example 1 Dehydrochlorination agent and sodium carbonate were replaced with urotropin 3/1.7 jJ (0.25 mol) and sodium hydroxide J, 0.0 g (0.4.0 mol) ) was processed in the same manner as in [flJ], but the target product...) could not be obtained.

Example 3.4 40.6 g (0.50 mol) of sodium acetate were used in the reaction step. In addition, 250 m of washing water is used in the post-treatment process.
, e was used, except that methanol recrystallization was additionally adopted.
It was treated in the same manner as in Example 1.

The results are not shown in Table 1.

For comparison, Ij2 was treated in the same manner as in Example 4 except that no solvent and methanol were used. Although the reactant solidified in the flask during the reaction step, the post-treatment step was continued by force. The results are shown in Table 2.

Table 2 Comparative Example 3 The process was carried out in the same manner as in Example 1 except that water and toluene were used instead of methanol as the solvent. In the latter case, the reaction product solidified during the tucking-carp step (water washing).

patent applicant Daicel Chemical Industries, Ltd.

Claims (1)

[Scope of Claims] 1) Reaction of methylene dianiline and monochloroacetic ester by dechlorination (conveniently using a weak alkali metal base 111 compound as a base agent) in methanol medium M. I] 11" direction and 4, Ryo-His (carboalcogine methylene amino 2) dehydrochlorination agent, sodium carbonate or hydrogen carbonate) l) Rum Tearo Tokuba '1 Claim 1 Method described.