Abstract: A blankmask for EUV lithography includes a substrate, a reflective layer, a capping layer, and a phase shift layer. The phase shift layer is made of a material containing ruthenium (Ru) and chromium (Cr), and a total content of ruthenium (Ru) and chromium (Cr) is 50 to 100 at %. The phase shift layer may further contain boron (B) or nitrogen (N). The phase shift layer of the present invention has a high relative reflectance (relative reflectance with respect to a reflectance of the reflective layer under the phase shift layer) with respect to a tantalum (Ta)-based phase shift layer and has a phase shift amount of 170 to 230°. It is possible to obtain excellent resolution when finally manufacturing a pattern of 7 nm or less by using a photomask manufactured using such a blankmask.

Abstract: The present invention relates to a novel, high-yield and low-cost method for preparing entecavir, [1-S-(1?,3?,4?)]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one, an antiviral agent, and novel intermediates used therein.

Abstract: Provided is a method of preparing a (6R)-3-hexyl-4-hydroxy-6-undecyl-5,6-dihydropyran-2-one, and a (5R)-2-hexyl-5-hydroxy-3-iminohexadecanoate derivative used in said method as an intermediate.

Abstract: The present invention relates to a novel, high-yield and low-cost method for preparing entecavir, [1-S-(1?,3?,4?)]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one, an antiviral agent, and novel intermediates used therein.

Abstract: Provided is a method of preparing a (6R)-3-hexyl-4-hydroxy-6-undecyl-5,6-dihydropyran-2-one, and a (5R)-2-hexyl-5-hydroxy-3-iminohexadecanoate derivative used in said method as an intermediate.

Abstract: Optically pure clopidogrel can be prepared in a high yield by optically resolving a racemic form of the compound of formula (II) using an optically active amine to form the optically active form of the compound of formula (III) or its acid-addition salt; and methylating the compound of formula (III) or its acid-addition salt.

Abstract: The present invention discloses a non-hygroscopic crystalline bepotastine metal salt hydrate, a method for preparing same, and a pharmaceutical composition comprising same for treating or preventing a histamine-mediated disease or an allergic disease.

Abstract: Optically pure clopidogrel can be prepared in a high yield by optically resolving a racemic form of the compound of formula (II) using an optically active amine to form the optically active form of the compound of formula (III) or its acid-addition salt; and methylating the compound of formula (III) or its acid-addition salt.

Abstract: Optically pure clopidogrel can be prepared in a high yield by optically resolving a racemic form of the compound of formula (II) using an optically active amine to form the optically active form of the compound of formula (III) or its acid-addition salt; and methylating the compound of formula (III) or its acid-addition salt.

Abstract: A crystalline clopidogrel naphthalenesulfonate or a hydrate thereof, a method for preparing same, and a pharmaceutical composition containing same are provided.

Abstract: Optically pure clopidogrel can be prepared in a high yield by optically resolving a racemic form of the compound of formula (II) using an optically active amine to form the optically active form of the compound of formula (III) or its acid-addition salt; and methylating the compound of formula (III) or its acid-addition salt.

Abstract: High purity cefdinir is prepared in a high yield by a process comprising the steps of: treating a crystalline salt of a cefdinir intermediate with a formic acid-sulfuric acid mixture or a formic acid-methanesulfonic acid mixture to obtain a crystalline salt of cefdinir and reacting the crystalline salt with a base in a solvent.

Abstract: A 3-(Z)-propenyl cephem compound is selectively prepared by reacting a phosphoranylidene cephem compound with acetaldehyde in the presence of a base in a solvent mixture comprising diethyl ether, formula (I), wherein R is a carboxyl protecting group; R1 is hydrogen or R2CH2CO—; and R2 is ethyl, 2-thiophenyl, phenyl, p-hydroxyphenyl or phenoxy

Abstract: High purity cefdinir is prepared in a high yield by a process comprising the steps of: treating a cefdinir intermediate with a formic acid-sulfuric acid mixture or a formic acid-methanesulfonic acid mixture to obtain a crystalline salt of cefdinir and reacting the crystalline salt with a base in a solvent.

Abstract: A 3-(Z)-propenyl cephem compound is selectively prepared by reacting a phosphoranylidene cephem compound with acetaldehyde in the presence of a base in a solvent mixture comprising diethyl ether, formula (I), wherein R is a carboxyl protecting group; R1 is hydrogen or R2CH2CO—; and R2 is ethyl, 2-thiophenyl, phenyl, p-hydroxyphenyl or phenoxy.

Abstract: 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid of formula (I) can be easily prepared by reacting 7-aminocephalosporanic acid of formula (II) with an azeotropic mixture of trimethyl borate and methanol in the presence of methanesulfonic acid:

Abstract: High purity cephalosporin compound can be easily prepared in a high yield by a process comprising the steps of: reacting a cephem compound with a 4-hydroxyphenylglycine derivative.