Abstract: The present invention provides a heterocyclic compound represented by the formula (I), its stereoisomers, or a pharmaceutically acceptable salt thereof, pharmaceutical compositions thereof, and their use in preparing a medicament for the prevention and/or treatment of central nervous system disease.

Abstract: The present invention provides a heterocyclic compound represented by the formula (I), its stereoisomers, or a pharmaceutically acceptable salt thereof, pharmaceutical compositions thereof, and their use in preparing a medicament for the prevention and/or treatment of central nervous system disease.

Abstract: The present invention relates to new salts of pyrazolopyrimidinone represented by formula (I), and pharmaceutically acceptable polymorph, solvate, hydrate, dehydrate, co-crystallization, anhydrous, or amorphous form thereof, the pharmaceutical compositions, and a pharmaceutical unit dosage form containing the same, wherein x represents organic or inorganic acids, preferable maleic acid, succinic acid, methanesulfonic acid, hydrochloric acid, etc. The invention further relates to co-crystals or complexes of compounds of pyrazolopyrimidinone and pharmaceutical compositions containing the same. The present invention also relates to a process for the preparation, use thereof and pharmaceutical preparation containing the salts or crystalline forms.

Abstract: This invention disclose (2R)-2-deoxy-2,2-disubstituted-ribono-1,4-lactone in a single configuration and preparation method and use thereof. The (2R)-2-deoxy-2,2-disubstituted-ribono-1,4-lactone, or a pharmaceutically acceptable salt, an ester, a prodrug or a solvate thereof according to the invention are important intermediates of a variety of anti-viral and anti-tumor active ingredients. A compound obtained from (2R)-2-deoxy-2,2-disubstituted-ribono-1,4-lactone via an acylation reaction can be directly used for preparing various anti-viral and anti-tumor drugs. The Chiral synthesis method and the spontaneous resolution method of the compound of (2R)-2-deoxy-2,2-disubstituted-ribono-1,4-lactone according to the invention have the following advantages: the reaction routes are short and simple with high yield and low cost, which are suitable for industrial application.

Abstract: Provided is a process for preparing racemic nicotine from 1-methyl-3-nicotinoyl-2-pyrrolidone or a salt thereof using one-pot process. The process comprises the following steps: 1) in a reaction vessel, reacting 1-methyl-3-nicotinoyl-2-pyrrolidone or a salt thereof in the presence of a suitable solvent and a strong acid by heat; after the reaction is complete, cooling the same and adjusting the pH to 7-8 with alkali; and 2) directly adding a reductant into the above vessel, and after the reaction, purifying the product so as to obtain high purity racemic nicotine or a salt thereof.

Abstract: The present invention relates to a class of phenylpyrimidone compounds, the pharmaceutical composition, the preparation method and the use thereof. More specifically, the present invention relates to a type of phenylpyrimidone compounds of the following formula I, the pharmaceutically acceptable salts or solvates thereof and to the pharmaceutical composition as well as the preparation method of the compounds. The compounds of formula I according to the present invention can effectively inhibit type V phosphodiesterase (PDE5), and thus can be used for the treatment of various vascular disorders, such as male erectile dysfunction, pulmonary hypertension and the like.

Abstract: Provided is a process for preparing racemic nicotine from 1-methyl-3-nicotinoyl-2-pyrrolidone or a salt thereof using one-pot process. The process comprises the following steps: 1) in a reaction vessel, reacting 1-methyl-3-nicotinoyl-2-pyrrolidone or a salt thereof in the presence of a suitable solvent and a strong acid by heat; after the reaction is complete, cooling the same and adjusting the pH to 7-8 with alkali; and 2) directly adding a reductant into the above vessel, and after the reaction, purifying the product so as to obtain high purity racemic nicotine or a salt thereof.