Abstract: The present invention relates to a method for preparing a tricyclic derivative, and more particulary, to a method for preparing a tricyclic derivative inetermediate with high yield and purity, the method including: introducing a hydroxy group by esterifying and substituting 2-fluoroisophthalic acid compound; introducing a piperidyl group; introducing a hydroxy group through reduction reaction; and then hydrolyzing the resultant compound, and to a method for preparing the tricyclic derivative using said intermediate. According to the method of the present invention, it is possible to provide a tricyclic derivative and an intermediate thereof with high productivity and economic feasibility as well as high purity and yield, by purifying a compound using re-crystallization unlike typical methods of using column chromatography.

Abstract: The invention in one embodiment is directed to a method of preparing a compound of formula 1, or a pharmaceutically acceptable salt thereof, wherein R1 and R2 are each independently chosen from hydrogen, (C1-C6)alkyl, and cycloalkyl, R is —NR3R4, where R3 and R4 are each independently chosen from hydrogen, and (C1-C4)alkyl; and n ranges from 1-4, comprising: (a) reacting a C1-C12 alkyl nitrate with a compound of formula 2, or a salt thereof, in the presence of an acid at a concentration greater than 70% weight of acid/weight of solution, the acid being selected from the group consisting of sulfuric acid, and R5—SO3H wherein R5 is C1-C4 alkyl optionally substituted with one or more halogen, or R5 is C6-C10 aryl optionally substituted with one or more C1-C4 alkyl or halogen, to produce a reaction mixture containing a compound of formula 3 or a salt thereof; (b) reducing the compound of formula 3 or a salt thereof to form a compound of formula 4 or a salt thereof (c) acylating the compound of for

Abstract: The invention relates to methods for preparing substituted cyclopentene compounds, their intermediates and use as neuraminidase inhibitors.

Abstract: Compounds of formula (I) where R1 is hydrogen; R2 is nitro, cyano or halo(lower)alkyl; R3 is phenyl substituted with one or more substituents selected from halogen, cyano and lower alkoxy; A is a lower alkylene group; R4 is a group CR6R7R8 wherein R6 and R7 form, together with the carbon atom to which they are attached a cycloalkyl group optionally substituted with hydroxy, lower alkoxy or a lower alkanoylamino; and R8 is hydrogen; its prodrug and a salt thereof.

Abstract: This invention pertains to chemical intermediates for a new class of 2-haloacetanilide herbicides and a process for preparation of these intermediates. The process generally involves nitration of substituted benzotrifluoride compounds.

Abstract: The present invention is directed to a process for preparing 5-nitro-acet-2,4-xylidine comprising:(a) dissolving acet-2,4-xylidine in an aqueous sulfuric acid solution, said aqueous solution containing from 86 to 92% by weight of sulfuric acid, the weight ratio of sulfuric acid to acet-2,4-xylidine being from 3.5:1 to 6.5:1;(b) nitrating the resultant solution at a temperature of from 0.degree. to 15.degree. C. in a mixed acid containing nitric acid, sulfuric acid, and from 10 to 25% by weight water; and(c) recovering 5-nitro-acet-2,4-xylidine.

Abstract: A process for the preparation of 5-amino-2,4-dimethylacetanilide by reduction of 5-nitro-2,4-dimethylacetanilide with hydrogen is disclosed characterized in that a crude mixture containing 5-nitro-2,4-dimethylacetanilide in admixture with at least one of its position isomers is hydrogenated in a water-miscible organic solvent which optionally contains water. The 5-amino-2,4-dimethylacetanilide is separated off from the reaction mixture by means of crystallization employing a mixture of water-miscible organic solvent and water.

Abstract: This invention describes a novel process whereby meta-substituted anilides are nitrated in the para position in high yields.