Process for the synthesis anthranilic diamide compounds and intermediates thereof

A process for the synthesis of a compound of formula (VI),

• wherein,
• R1 is C1-C4 alkyl or halogen;
• R2 is hydrogen, halogen or cyano;
• R3a and R3b are independently hydrogen, C1-C4 alkyl or C3-C6 cycloalkyl-C1-C4 alkyl;
• R3c is hydrogen or C1-C4 alkyl;
• comprising the steps of:
• a) converting an anthranilic amide compound of formula (Va) into a N-substituted anthranilic amide compound of formula (VI) by either of the following steps:
• i. in the presence of a suitable base or a suitable acid and a suitable alkylating reagent,
• ii. by using suitable transamidation process,
• according to the reaction scheme as depicted below:
• or
• converting an anthranilic acid compound of formula (V) into a N-substituted anthranilic amide compound of formula (VI) using a suitable amine of formula HN(R3a)(R3b) and a suitable coupling reagent, according to the reaction scheme as depicted below:
• b) converting a mono- or dicyano substituted aniline compound of formula (IV) into the anthranilic acid compound of formula (V) or the anthranilic amide compound of formula (Va) optionally in the presence of a suitable base or a suitable acid, according to the reaction scheme as depicted below:
• or
• converting a mono- or dicyano substituted aniline compound of formula (IV) into the N-substituted anthranilic amide compound of formula (VI) by either of the following reaction steps:
• i) in the presence of a suitable base or a suitable acid and a suitable alkylating reagent,
• ii) aminolysis using a suitable amine of formula HN(R3a)(R3b)
• according to the reaction scheme as depicted below:
• c) optionally, halogenating a mono- or dicyano substituted aniline compound of formula (IV), wherein R1 and/or R2 are hydrogen in the presence of a suitable halogenating agent to obtain a mono- or dicyano substituted aniline compound of formula (IV), wherein R1 and/or R2 are halogen;
• d) converting a mono-, di-, or tri-halogenated aniline compound of formula (III) wherein X is halogen, into the mono- or dicyano substituted aniline compound of formula (IV) using a suitable cyanation reagent according to the reaction scheme as depicted below:
• e) converting a substituted aniline compound of formula (II) into the mono-, di-, or tri-halogenated aniline compound of formula (III) wherein X is halogen, using a suitable halogenating agent, according to the reaction scheme as depicted below:

A process for the synthesis of an anthranilic acid compound of formula (V) or an anthranilic amide compound of formula (Va),

• wherein,
• R1 is C1-C4 alkyl or halogen;
• R2 is hydrogen, halogen or cyano;
• R3c is hydrogen or C1-C4 alkyl;
• comprising the steps of:
• a) converting a mono- or dicyano substituted aniline compound of formula (IV) into an anthranilic acid compound of formula (V) or an anthranilic amide compound of formula (Va) optionally in the presence of a suitable base or a suitable acid according to the reaction scheme as depicted below:
• or
• converting a mono- or dicyano substituted aniline compound of formula (IV) into a N-substituted anthranilic amide compound of formula (VI) by either of the following reaction steps:
• i) in the presence of a suitable base or a suitable acid and a suitable alkylating reagent,
• ii) aminolysis using a suitable amine of formula HN(R3a)(R3b) according to the reaction scheme as depicted below:
• b) optionally, halogenating a mono- or dicyano substituted aniline compound of formula (IV), wherein R1 and/or R2 are hydrogen in the presence of a suitable halogenating agent to obtain a mono- or dicyano substituted aniline compound of formula (IV), wherein R1 and/or R2 are halogen;
• c) converting a mono-, di-, or tri-halogenated aniline compound of formula (III) wherein X is halogen, into the mono- or dicyano substituted aniline compound of formula (IV) using a suitable cyanation reagent, according to the reaction scheme as depicted below:
• d) converting a substituted aniline compound of formula (II) into the mono-, di-, or tri-halogenated aniline compound of formula (III) wherein X is halogen, using a suitable halogenating agent, according to the reaction scheme as depicted below: