Abstract: The present disclosure provides a process for preparation of 3,6-dichlorocyano pyrazine, 3,6-dioxopiperizine derivatives and production of favipiravir via ammonia or amine-mediated cyclization and chlorination using POCl3 in the presence of pyridine or PCl5. [Formula] wherein in 3,6-dioxopiperazine derivatives (III), X is CN, CONH2 or COOR2?, R1, R2 and R2? are individually selected from H, C1-C12 alkyl, COOR3 and SO2R3 wherein R3 is substituted or unsubstituted linear or branched lower alkyl.

Abstract: The present invention relates to a process for the preparation of tapentadol and analogs or compounds or stereoisomers of formula (I), Formula I wherein, A is aryl, heteroaryl, and cycloalkyl; R is H, OH, OR1, halogen, C1-C12 alkyl, cycloalkyl, aryl or heteroaryl; R1 is C1-C12 alkyl, cycloalkyl, aryl or heteroaryl, wherein each of these groups may further be substituted with one or more substituent selected from H, OH, halogen, CN, NO2, C1-C4 alkyl or phenyl. Further, the multi-step process involves no column chromatography purification until the very last step. This makes this process highly commercially viable and industrially useful.

Abstract: Sulfonyl hydroxamic acid compounds have the following general formula: Ring A and B are aryl, heteroaryl, cycloalkyl, fused aryl or fused alkyl group, and R1, R2, R3, R4, R5, and R6 are hydrogen, alkoxy, aryloxy, hydroxy, ester, amide, amino, alkyl, aryl, heteroaryl, halogen, hydroxy, alkoxy, aryloxy, nitro, cyano, ester, or aldehyde. The compounds are HDAC inhibitors. Processes can be used for preparation of these indole-based sulfonyl hydroxamic acid derivatives.

Abstract: Sulfonyl hydroxamic acid compounds have the following general formula: Ring A and B are aryl, heteroaryl, cycloalkyl, fused aryl or fused alkyl group, and R1, R2, R3, R4, R5, and R6 are hydrogen, alkoxy, aryloxy, hydroxy, ester, amide, amino, alkyl, aryl, heteroaryl, halogen, hydroxy, alkoxy, aryloxy, nitro, cyano, ester, or aldehyde. The compounds are HDAC inhibitors. Processes can be used for preparation of these indole-based sulfonyl hydroxamic acid derivatives.

Abstract: The present invention relates to a process for the preparation of (1-alkylindol-3-ylmethyl) benzoic acid derivatives, in particular Zafirlukast and analogs thereof. Further, this process is based on protection group free and C—H bond activation strategy involving all step catalytic transformation sequence and comprises the following steps: Sonogashira coupling, indole formation by Sp3 C—H activation, reductive hydrogenation and amidation.

Abstract: The present invention relates to a process for the preparation of (1-alkylindo-3-ylmethyl) benzoic acid derivatives, in particular Zafirlukast and analogs thereof. Further, this process is based on protection group free and C—H bond activation strategy involving all step catalytic transformation sequence and comprises the following steps: Sonogashira coupling, indole formation by Sp3 C—H activation, reductive hydrogenation and amidation.