摘要:
A process for preparing a crystalline, carbapenem monosodium salt of formula IIa: characterized by the steps a) adding about 10 to 30% of an organic solvent to an aqueous solution of the carbapenem, b) cooling the resulting solution to less than −5° C., c) adjusting the pH using a solution containing an acid in an organic solvent to give the appropriate pH for crystallization, and d) crystallizing the compound by adding methanol, and a C2-5 alcohol at between −5 and −25° C.
摘要:
A process for preparing a crystalline, carbapenem monosodium salt of formula IIa: characterized by the steps a) adding about 10 to 30% of an organic solvent to an aqueous solution of the carbapenem, b) cooling the resulting solution to less than −5° C., c) adjusting the pH using a solution containing an acid in an organic solvent to give the appropriate pH for crystallization, and d) crystallizing the compound by adding methanol, and a C2-5 alcohol at between −5 and −25° C.
摘要:
The present invention relates to a process for reducing the levels of organic solvents to pharmaceutically acceptable levels in thermally unstable crystalline carbapenem solids represented by formula I: or a salt thereof, wherein R1 and R2, are the same or different, and are selected from H, alkyl, aryl, and heteroaryl, comprising washing a carbapenem solid containing organic solvent with an organic solvent containing water; and using vacuum and/or inert gas (hydrated or dry) at low temperature to produce a compound of formula I containing pharmaceutically acceptable levels of organic solvents, wherein the water content of the crystalline carbapenem solid, correcting for organic solvents, is maintained at about 13% to about 25% during the process.
摘要:
The present invention is concerned with a novel process for the preparation of 3,5-bis(trifluoromethyl)bromobenzene (CAS 328-70-1). This compound is useful as an intermediate in the synthesis of compounds which possess pharmacological activity.
摘要:
An improved process for formation of a 5-oxime on avermectin derivatives comprises the treatment of the oxo-compound with hydroxylamine in aqueous isopropanol at pH 1.8-2.1.
摘要:
An improved process for formation of a 5-oxime on avermectin derivatives comprises the treatment of the oxo compound with O-(trimethylsilyl)hydroxylamine in the presence of a Lewis acid.
摘要:
The present invention is concerned with a novel process for the preparation of 1-(3,5-bis(trifluromethyl)phenyl)ethan-1-one (CAS 30071-93-3). This compound is useful as an intermediate in the synthesis of therapeutic agents.
摘要:
The present invention relates to a process for converting a racemic mixture of 3,3-diethyl-4-[(4-carboxy)phenoxy]-2-azetidinone esters into the corresponding (S)-acid using lipase derived from Pseudomonas sp. The process provides the target acid in high enantiomeric excess.
摘要:
A 4"-oxoavermectin intermediate is reductively aminated using hexa- or heptamethyldisilazane and sodium borohydride to produce a 4"-amino (or methylamino)avermectin. The 4"- aminoavermectin is a useful intermediate in the preparation of N-acyl derivatives. The compounds are useful as agricultural and animal health insecticides and parasiticides.
摘要:
A novel process is provided for the preparation of pyrrolidine carboxylic acids, and the useful intermediates obtained therein. These compounds are intermediates for the synthesis of melanocortin-4 receptor (MC-4R), which are useful for the treatment of disorders such as obesity, diabetes, sexual dysfunction, male sexual dysfunction, and female sexual dysfunction.