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.

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.