Application of 2-amino-2-methyl-1-propanol_Industrial additives

Overview^[1][2]

2-Amino-2-methyl-1-propanol, referred to as AMP, is a multifunctional additive for formulating environmentally friendly latex paints. It can also be used as an organic base and pharmaceutical intermediate for other neutralizing and buffering purposes, such as biochemical Buffers and activators for diagnostic reagents. 2-Amino-2-methyl-1-propanol can improve and strengthen many coating components and enhance the effects and performance of other additives. AMP can improve the scrub resistance, hiding power, viscosity stability, color development, etc. of coatings. Adding ammonia to coatings can provide many advantages such as reducing system odor and reducing tank corrosion and flash rust.

Preparation^[1]

The foreign production process of 2-amino-2-methyl-1-propanol is synthesized by using 2-nitropropane as raw material, such as Angus and Dow’s AMP-95 in the United States, which can synthesize 2-nitropropane. -Nitropropane first reacts with formaldehyde to formylate, then reduces the nitro group, and then separates to obtain 2-amino-2-methyl-1-propanol. The synthetic route using 2-nitropropane as raw material has its shortcomings. The raw material is dangerous, difficult to store and transport, requires large investment in production equipment, and is difficult to prepare high-purity 2-amino-2-methyl-1-propanol.

Method 1. In order to solve the shortcomings in the existing technology that the raw materials for 2-amino-2-methyl-1-propanol synthesis are dangerous, the production investment is large, and the product is difficult to purify, CN200610053023.4 provides a raw material that is easy to purify. A method for preparing amino-2-methyl-1-propanol with low cost and easy product purification.

Put 205.5g of acetonitrile (5mol) into a 500ml glass tube reactor. Connect the two interfaces of the reaction bottle to the bottom tube. One is connected to the chlorine gas source, the other is connected to the isobutylene source, and a thermometer is installed on the other. Place the reaction bottle into a 0°C ice water bath, start the magnetic stirring, and wait until the system temperature drops to 0°C. At the same time, 63.8g (0.9mol) chlorine and 50.5g (0.9mol) isobutylene are introduced into the reaction bottle in the same proportion. After aeration, continue stirring for half an hour, then add dropwise 11g of water (0.6 mol), stir for half an hour after the dropwise addition, and then filter. The filtrate is vacuum concentrated at about 45°C to obtain 83g of slightly yellow concentrated liquid. Dissolve the concentrated solution obtained in the previous step with 41.5g of ethanol solution with a volume concentration of 95%, heat and stir until refluxing, then add 29.05g of concentrated hydrochloric acid with a weight concentration of 37%, heat to reflux for about 2 hours, and then distill the system while heating. water, ethanol and ethyl acetate, etc., then add 41.5g of ethanol solution and 12.45g of concentrated hydrochloric acid and continue to reflux for about 2 hours. The solvent is distilled out while heating. Add water to the concentrate and then vacuum distill it until there is no more distillate. , the obtained 66g of viscous white solid is the hydrochloride of AMP.

The white AMP hydrochloride intermediate obtained in the previous step was neutralized with 55g of sodium hydroxide solution with a mass concentration of 40% until the pH=12. The water in the system was evaporated under reduced pressure, and then used with an ethanol solution with a volume concentration of 95%. Extraction, filtration, and ethanol were evaporated from the filtrate under reduced pressure to obtain 40 g of crude amp product, with a yield of isobutylene of 50%. The obtained crude 2-amino-2-methyl-1-propanol is distilled to prepare a high-purity product with a content of ≥99%.

Method 2, CN201510712516.3 reports a method for synthesizing 2-amino-2-methyl-1-propanol from isopropylamine. The isopropylamine and synthesis gas are mixed in a metal catalyst, ligand and solvent. In the presence of , react at 100-200°C and 0.8-20MPa to obtain the 2-amino-2-methyl-1-propanol.

Take 300g of diphenyl ether, 30g of isopropylamine (0.51mol), 11.25g of palladium acetate (50mmol) and 65.5g of triphenylphosphine (250mmol), and add them to a 1000mL autoclave in sequence, and pass the synthesis gas into The pressure in the autoclave is 3MPa, and the synthesis gas is a mixed gas of H₂ and CO with a molar ratio of 1:1. Start stirring and raise the temperature to 140°C. When the temperature rises to 140°C, use synthesis gas to supplement the pressure to 8MPa and start the timing reaction. During the reaction process, the synthesis gas pressure was intermittently supplemented to maintain the reaction pressure at 7 to 8 MPa. Gas chromatography tracking found that isopropylamine was no longer converted after 6 hours, and the temperature was lowered to stop the reaction.

Take out the reaction solution, distill it under reduced pressure at 2.5kPa, collect the fraction between 68 and 72°C, and obtain 40.85g of pure 2-amino-2-methyl-1-propanol, with a yield of 90%. At the same time, 422g of distillation still liquid was obtained.

The spectral data of pure 2-amino-2-methyl-1-propanol are as follows:

¹H NMR (300MHz, CDCl₃, TMS as internal standard): 3.27(s,2H,-CH₂-) ,2.60(brs,3H,-OH,- NH₂),1.09(s,6H,CH₃-)��

FT-IR (KBr, σ/cm^-1): 3340 (N-H st and O-H st), 2966 (C-H st), 1595 (N-Hδ), 1380 (C-Hδ) ), 1310(C-N st), 1068(C-O st).

Figure 1 shows the hydrogen nuclear magnetic spectrum of pure 2-amino-2-methyl-1-propanol;

Figure 2 is the infrared spectrum of pure 2-amino-2-methyl-1-propanol.

Apply^[3-4]

CN200610028459.8 reports an improved method for preparing water-free hand sanitizer, which will contain ethanol, carbomer, deionized water, 2-amino-2-methyl-1-propanol, propylene glycol, and triclosan The components of glycerol are assembled according to the following steps:

(1) Stir and heat carbomer and deionized water in a vacuum worm gear mixer at 40~45°C until completely dispersed; then cool down, add ethanol, stir and mix; then add 2-amino-2-methyl -1-Propanol; this phase A reactant rotates rapidly with the blades of the vacuum turbine mixer.

(2) In another mixer, add triclosan to propylene glycol and fully dissolve it to become phase B reactant; pour phase B reactant into phase A reactant and mix. (3) Then slow down the speed of the vacuum worm gear mixer, add glycerol and mix to form the C phase product; take the C phase product out of the machine at room temperature. According to the preparation method of the improved water-free hand sanitizer of the present invention, the preparation technology and preparation process are simple. The improved water-free hand sanitizer prepared by the preparation method of the present invention is an updated product, which has little skin irritation, mild action, strong detergency, and plays the role of disinfection and sterilization.

CN200810158538.X reports a waterproof aerosol sunscreen and its preparation method, which consists of special denatured ethanol, 2-amino-2-methyl-1-propanol, deionized water, and octyl methoxycinnamate. , methyl anthranilate, cyclomethylsiloxane, tocopheryl acetate, and dimethyl ether are mixed in a certain proportion. Each sunscreen contains 40% to 45% special denatured ethanol, 0.35% to 0.5% 2-amino-2-methyl-1-propanol, 7.5% to 10% octyl methoxycinnamate, and aniseed. Methyl acid ester 4%~6%, cyclomethicone 3%~4%, tocopherol acetate 0.5%~0.8%, dimethyl ether 30%~35%, the balance is deionized water. Combine the special denatured ethanol with 2-amino-2-methyl-1-propanol and mix until complete. Add the other components except dimethyl ether. Continue mixing until thorough. Filter and add dimethyl ether to fill. It can be applied directly to the face, absorbs ultraviolet rays, prevents skin from sunburn, and resists being washed away by large amounts of water.

Main reference materials

[1] CN200610053023.4 Preparation method of 2-amino-2-methyl-1-propanol

[2] CN201510712516.3 A method of synthesizing 2-amino-2-methyl-1-propanol from isopropylamine

[3] CN200610028459.8 Preparation method of water-free hand sanitizer

[4] CN200810158538.X Waterproof aerosol sunscreen and preparation method thereof