JPS6026395B2 - Synthesis method of N-trialkylsilylmethylurea - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for the synthesis of N-trialkylsilylmethylureas.

It is known that N-trimethylsilylmethylurea m can be synthesized from chloromethyltrimethylsilane 1 by the following method.
tamcChemistry, 44, 279, (197
2).

(Here, Me represents a methyl group.

) This method requires the reaction of chloromethyltrimethylsilane (1) of formula 1) and ammonia to be carried out under pressure, and the yield of trimethylsilylmethylamine (0) is low, and the number of moles of chloromethyltrimethylsilane is low. Disadvantages include that the yield of N-trimethylsilylmethylurea (m) is extremely low based on , and that two steps 1) and 2) are required to produce (m).

As a result of extensive research into these problems, the present inventors have discovered a method for obtaining N-trimethylsilylmethylurea under normal pressure using chloromethyltrimethylsilane as a raw material.

That is, the purpose of the present invention is to provide a production method for obtaining N-trialkylsilylmethylurea in high yield using chloromethyltrialkylsilane as a raw material in a simpler manner than conventional methods, that is, to provide an industrial synthesis method. It is in. The synthesis method of the present invention involves reacting chloromethyltrialkylsilane and cyanate in a dimethylformamide solvent in the presence of tetraethylammonium iodide at a temperature of 50 to 150°C, and then adding ammonia at a temperature of -20°C. It is characterized in that N-trialkylsilylmethylurea is obtained by reacting with ~13 and ○.

The chloromethyltrialkylsilane of the present invention has the general formula R
3SIC ratio CI (wherein R represents the same or different alkyl group having 1 to 5 carbon atoms.

), specifically, chloromethyltrimethylsilane, chloromethyltriethylsilane, chloromethyltripropylsilane, chloromethyldimethylethylsilane,
Examples include chloromethyldimethyl t-butylsilane. In addition, N obtained by the synthesis method of the present invention
Trialkylsilylmethylurea is represented by the general formula R3SIC2NHCONH2 (R is the same as above). Examples of cyanates include potassium cyanate and sodium cyanate. The amount used is 1 to 2 equivalents per equivalent of chloromethyltrialkylsilane. In the synthesis method of the present invention, tetraethylammonium diodide is used as a catalyst, and the amount used is 0.01 to 0.0% per equivalent of chloromethyltrialkylsilane.
It is 5 equivalents. Dimethylformamide, dimethylacetamide, etc. can be used as a solvent. In the synthesis method of the present invention, chloromethyltrialkylsilane, cyanate, and tetraethylammonium diodide are added to a solvent in a reactor at a temperature of 50 to 15,000, preferably 80 to 150q.
o, most preferably from 90 to 11 p0, and the reaction is usually stirred.

The time is not particularly limited, but is usually 0.1 to 2 hours. After the reaction, the temperature of the reaction solution is set at -20 to 13,000 and ammonia gas is blown into the solution for further reaction, or the reaction solution is dropped into concentrated aqueous ammonia for reaction. After removing inorganic salts produced as the reaction progresses, N-trialkylsilylmethylurea can be obtained from the reaction solution by extraction, recrystallization, or other methods. The synthesis method of the present invention allows N-trialkylsilylmethylurea to be obtained from chloromethyltrialkylsilane in a higher yield than conventional methods.

In addition, the process is simpler than conventional methods, making it an excellent industrial method. Trialkylsilyldiazomethane V is obtained from the N-trialkylsilylmethylurea W obtained in the present invention by the following reaction, and this trialkylsilyldiazomethane V can be obtained by "homologation reaction of carbonyl compounds", "Arunto-Eistert synthesis", etc. ”, etc., can be effectively used in the improved method by the present inventors.

R3M ratioNHCONH2NH02RbuiC ratioNCONH
2(iv) NO mold board type base R3SIC 洲20R3SiOSiR3 [v] The present invention will be described below with reference to Examples and Comparative Examples.

The yields shown in Examples and Comparative Examples are values based on the number of moles of chloromethyltrimethylsilane. Example 1 Into a 500-meter inner mirror reactor, 240 ml of dimethylformamide was added as a solvent, and to this were added 30 ml (245 mmol) of chloromethyltrimethylsilane and 33.1 ml (367 mmol) of potassium cyanate (90% purity). ), and 2.9 hours of tetraethylammonium iodide as a catalyst (11.
3 mmol) and mix.

This mixed solution was heated to 10,000 for 20 minutes and stirred for 400 minutes to carry out a reaction. After that, the reaction solution was cooled on ice, and ammonia gas was added at a rate of 150 m/min.
After a period of time, the reaction was further carried out. After the reaction, the inorganic salts precipitated in the reaction solution were separated in a furnace, and the furnace solution was concentrated under reduced pressure. 200 μl of water was added to the obtained residue, and the product was dissolved in a benzene-ethyl acetate (volume ratio 1:1) solvent. Extracted.

The extract was washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain a solid product. By recrystallizing this solid product from benzene, it has a melting point of 114-11,600.
(Literature value: 113-0114 qo) 21.6 days (yield: 60%) of N-trimethylsilylmethylurea was obtained. Comparative example 1.

In the same manner as in Example 1, 81 to The reaction was carried out at 820° C. for 2 hours, and the same procedure as in Example 1 was carried out to obtain 0.86 N-trimethylsilylmethylurea (yield: 6%). 0 Example 2 Into a reactor with an internal volume of 100 mm, 60 mm of dimethylformamide was charged as a solvent, and 12.25 mm (100 mmol) of chloromethyltrimethylsilane and 9.96 mm (100 mmol) of potassium cyanate (purity 90%) were added thereto. 110 mmol) and tetraethylammonium iodide 2 as a catalyst.
．． 57 (10 mmol) and mix.

The mixture was heated to 80-820°C in 15 minutes and stirred for 1 hour to carry out the reaction. Next, the reaction solution was cooled with ice, transferred to a dropping funnel, and added dropwise to 30' of concentrated ammonia water over 20 minutes while being cooled with ice. Soma) 43 intervals,
Then, the reaction was carried out by stirring at room temperature for 1 hour. The reaction solution was concentrated under reduced pressure, and 100 parts of water was added to the resulting residue, and the product was extracted with a solvent of benzene monoacetate (volume ratio 1:1). Thereafter, the same treatment as in Example 1 was carried out to obtain 056 N-trimethylsilylmethylurea (yield: 44.8%). Example 3 60% of dimethylformamide was placed as a solvent in a reactor with an internal volume of 100%, and 2.45% (20 mmol) of chloromethyltrimethylsilane and 1.99% (20 mmol) of potassium cyanate (purity 90%) were added to this. 0.26 mmol of tetraethylammonium iodide (2 mmol), and 0.26 mmol of tetraethylammonium iodide (2
mmol) and mix.

Heat this mixture to 145°C for 15 minutes and leave it there)
The reaction was stirred for 10 minutes. The following procedure was carried out in the same manner as in Example 3, and 1.17 hours of N-trimethylsilylmethylurea (
A yield of 40% was obtained.

Comparative Example 24.5 parts (200 mmol) of chloromethyltrimethylsilane and 150 parts of liquid ammonia were placed in a stainless steel pressure-resistant reactor with an internal volume of 500 cm, and the mixture was heated at 100° C. for 5 hours to carry out a reaction.

After lining, excess ammonia was removed, the remaining bamboo was dissolved in 20% hydrochloric acid, washed with ether, the hydrochloric acid layer was made alkaline with 20% aqueous sodium hydroxide solution, extracted with ether, dried with anhydrous magnesium sulfate, and the solvent was distilled off. A yellow oily product was obtained. By distilling this oil, the boiling point
9.7 hours of trimethylsilylmelamine (literature value gr) was obtained. Next, in a reactor with an internal volume of 200, 95
Add 100% ethanol and 9.7 mmol of trimethylsilylmethylamine obtained above.

Claims (1)

[Claims] 1. After reacting chloromethyltrialkylsilane and cyanate in the presence of tetraethylammonium iodide in a dimethylformamide solvent at a temperature of 50 to 150°C, ammonia is further reacted at a temperature of -20°C. A method for synthesizing N-trialkylsilylmethylurea, characterized by carrying out the reaction at ~+30°C. 2 Chlormethyltrialkylsilane has the general formula R_8S
The synthesis method according to claim 1, which is represented by iCH_2Cl (in the formula, R represents the same or different alkyl group having 1 to 5 carbon atoms).