34 results about "SN2 reaction" patented technology

The invention relates to a chiral synthesis method of (S)-3-aminopyrrolidine dihydrochloride, which uses trans-4-hydroxyl-L-proline as a raw material, first undergoes a decarboxylation reaction, and then performs N-tert-butyl Oxycarbonyl protection, hydroxyl sulfonylation, and then SN2 reaction with sodium azide, configuration inversion, after triphenylphosphine reduction of azido group to amino group, directly remove N-Boc protection with concentrated hydrochloric acid, a total of A four-step chain reaction yields the target product. The raw materials used in the inventive method are cheap and easy to obtain, the reaction conditions are mild, the aftertreatment is simple and convenient, and the yield of the obtained product is relatively high.

The invention discloses a synthesis method and application of a multi-target A beta oligomerization inhibitor. The synthesis method comprises the following steps: (1) taking bromaniline or derivatives thereof and (1-benzylpiperidine-4-yl)methylamine or derivatives thereof as starting raw materials, and carrying out Suzuki coupling reaction for preparing an intermediate II; (2) taking the intermediate II and 1,3-dibromopropane or other analogues as raw materials, and carrying out SN2 reaction for preparing an intermediate III with an alkyl chain; and (3) taking the intermediate III with the alkyl chain and imidazole or derivatives thereof as raw materials, and carrying out SN2 reaction for preparing the target product multi-target A beta oligomerization inhibitor. The synthesis method disclosed by the invention is simple and reliable in route, high in yield and more suitable for large-scale preparation. The multi-target A beta oligomerization inhibitor is applied to preparation of an A beta oligomerization inhibitor anti-AD medicine, a glutaminyl cyclase inhibitor anti-AD medicine and an acetylcholin esterase inhibitor anti-AD medicine and can be applied to kits of A beta oligomerization, glutaminyl cyclase and acetylcholin esterase.

The invention discloses a method for producing high-viscosity and high-degree-of-substitution carboxymethyl cassava starch by utilizing an ultrahigh-pressure blasting technique. The method comprises the steps such as alkaline treatment, etherification reaction and purification. The method is carried out by primarily achieving the purpose of destroying a crystallization region of cassava starch particles by utilizing sodium hydroxide, sufficiently swelling and alkalifying starch molecules and loosening starch particles under the ultrahigh pressure of a high-pressure homogenizer, so that the hydroxyl of the starch becomes negative oxygen ions and the nucleophilic ability is strengthened, and simultaneously generating an St-O-Na<+> active center, then, preparing the high-viscosity and high-degree-of-substitution carboxymethyl cassava starch through the bimolecular nucleophilic substitution between sodium carboxymethyl starch obtained by alkalifying the starch and chloroacetic acid under the alkaline condition of sodium hydroxide. By utilizing the high-degree destructive effect of the ultrahigh-pressure blasting technique on a crystallization structure of the cassava starch, the technical problems such as degradation of the starch particles in a production process of the high-viscosity and high-degree-of-substitution carboxymethyl cassava starch are solved.

The invention discloses a method for continuously preparing 4-(6-hydroxyhexyloxy)phenol in a micro-reactor. The method comprises the following steps: dissoling hydroquinone and 6-chloro-1-hexanol in the solvent ethanol; and with an alkali aqueous solution of NaOH<-> as a catalyst, carrying out a bimolecular nucleophilic substitution reaction in the micro-reactor so as to continuously prepare 4-(6-hydroxyhexyloxy)phenol. Compared with the prior art, the method provided by the invention has the following advantages that the synthesis time of 4-(6-hydroxyhexyloxy)phenol is reduced to 10 min or less from original 20 hours; yield is increased from original 40% to 80%;continuous operation during the reaction can be realized; and integration and enlargement can be easily realized.

The invention provides a preparation method of a green chelating agent. Specifically, under normal pressure conditions, the use of partially neutralized amino acids and chloroacetic acid produces S under the action of a catalyst. N 2 Bimolecular nucleophilic substitution reaction to prepare a series of green chelating agents, wherein the catalyst is iodide of alkali metal, and the amount of catalyst used is 0.01-0.30% of the input mass of amino acid. The method of the present invention adopts an atmospheric pressure catalytic reaction system, the catalyst usage is small, and the treatment method is simple; the catalytic performance is good, and the product yield can reach more than 96%; Chemical industry production.

The invention provides a novel preparation method of tetrasodium aspartic acid diacetate. Specifically, under certain temperature conditions, the partially neutralized natural amino acid L-aspartic acid is used as a raw material, and SN2 bimolecular nucleophilic substitution reaction occurs with chloroacetic acid under alkaline conditions to prepare tetrasodium aspartic acid diacetate. Among them, chloroacetic acid and sodium hydroxide are added dropwise into the kettle, and the pH value of the reaction system is controlled in the range of 9~12. At the same time, the reaction process is under the condition of 0~-0.005MPa negative pressure, and the water in the reaction system is removed in time to maintain Reaction material concentration, improve conversion rate and reaction rate. The method of the invention has short reaction period, simple production process, and the yield can reach 99%. The produced water can be recycled, no toxic by-products and waste water are produced, safe and environment-friendly, and easy to realize large-scale industrial production.

The invention discloses a sulfonate-type fluorosilicon anionic surfactant and a preparation method thereof. The preparation method uses an easily degradable, low-toxic fluorine-containing compound C 6 f 13 SO 2 F as the starting point, firstly, the bimolecular nucleophilic substitution (SN2) reaction with N-methallylamine was carried out to prepare NSF6, and then NSF6 was sequentially reacted with hydrogen-containing silicone oil (PMHS) and allyl glycidyl ether (AGE) for hydrosilation reaction, Finally with NaHSO 3 Sulfonate-type fluorosilicon anionic surfactant PSF6AS was synthesized by sulfonation reaction, and its surface tension and critical micelle concentration were measured. Compared with traditional fluorocarbon surfactants, this surfactant has better water solubility and biodegradability; it also provides a new research method and idea for the development and application of sulfonate-type fluorosilicon anionic surfactants in my country .

This invention relates to synthesis of precursor of intermediate of AG7088 type compounds, with its constructural formula as shown. Under N protection, coupling reaction of amino-aldehyde and propiolate is proceeded. Said product is hydrogenized with N protection base being substituted by Boc or other nucleophilic protection base. Said product is then hydroxylated activated. Then it is proceeded inner molecular SN2 reaction to produce oxazolon ane, then being reverse turning its hydroxy structure, adding N protection base, opening the ring of oxazolidone, under acid condition to close penta internal ester ring to obtain intermediate of AG7088. In this invention natural amino acid is used as raw material, with short synthesis process, high yield, good stereoselectivity.