Method for synthesizing imidazoline intermediate and cationic derivative thereof

Abstract

The invention relates to a method for synthesizing an imidazoline intermediate and a cationic derivative thereof. The method comprises the following process steps of: putting fatty acid, polyamine and water into a reaction kettle in a mole ratio of 1:1.1-2:1-5, heating to the temperature of between 100 and 180 DEG C to distill over the water added before and the water generated in the reaction, removing redundant polyamine and water under a pressure of between -0.04 and -0.1MPa and performing a reaction at a temperature of between 180 and 240 DEG C for 3 to 8 hours to synthesize the imidazoline intermediate; and reducing the temperature of the imidazoline intermediate to be below 80 DEG C, adding a solvent of which the mass is 30 to 100 percent of the imidazoline intermediate into the imidazoline intermediate, then adding 1 to 2mol of sulfate into the mixture and performing heat preservation reaction at the temperature of between 50 and 80 DEG C for 2 to 4 hours to synthesize cationic imidazoline. The fatty acid is oleic acid, linoleic acid, stearic acid, palmitic acid, lauric acid, coconut oil acid, capric acid and octanoic acid; the polyamine is ethylenediamine, diethylenetriamine, triethylene tetramine and tetraethylene pentamine; the solvent is isopropanol, absolute ethyl alcohol or 95 percent ethanol; and the sulfate is dithyl sulfate and dimethyl sulfate.

Description

technical field [0001] The invention relates to a synthesis method of an imidazoline intermediate and a cationic derivative thereof, belonging to the field of organic synthesis and chemical industry. Background technique [0002] Imidazoline surfactant is a kind of surfactant with excellent performance, low toxicity and easy biodegradation. The imidazoline intermediate can be used as an oil-soluble corrosion inhibitor, used as an additive for lubricating oil, anti-rust oil, and anti-rust paint. It has good corrosion inhibition effect and water film displacement. Cationic imidazolines can be used as water-soluble corrosion inhibitors for pickling corrosion inhibitors, preservatives, and fungicides. [0003] The imidazoline surfactants that are widely used in the market are mainly synthesized from asymmetric organic polyamines and fatty acids. Because imidazolines synthesized with symmetrical organic polyamines and fatty acids are prone to produce a large number of by-product...

AI Technical Summary

Problems solved by technology

The "solvent dehydration method" produces stable water, and the organic amine is not easy to carry out, but the product will be mixed with solvent, and the recovery of the solvent requires additional distillation equipment; although the "vacuum dehydration method" is easy to produce, it is easy to lose the organic amine, resulting in the bisamide content in the product High; although the synthesis of imidazoline by "step heating and free water outlet method" is not easy to lose organic amines and has less bisamide content, the incomplete water outlet makes the reaction incomplete, and it is easy to make polyamine residues

[0004] Cationic imidazoline is synthesized by the reaction of imidazoline intermediates and alkylating reagents. The alkylating reagents generally use chlorinated alkanes or sulfuric acid esters. The reaction speed of chlorinated alkanes is slow, and the generated chloride ions will affect the corrosion inhibition performance.

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