Process for the synthesis of anthranilic acid/amide compounds and intermediates thereof

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

• wherein,
• R1 is selected from the group consisting of halogen, C1-C4 alkyl and C3-C4-cycloalkyl;
• R2 is selected from the group consisting of hydrogen, halogen, cyano, C1-C4 alkyl and C3-C4-cycloalkyl;
• R3 is selected from the group consisting of hydrogen, halogen, cyano, C1-C4 haloalkyl and C3-C6 cycloalkyl;
• R4aR4b wherein R4a and R4b are independently selected from the group consisting of hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, and C3-C6 cycloalkyl-C1-C4 alkyl;
• comprising a) through d)
• a) reacting a compound of formula (II) with a compound of formula (III) to afford a compound of formula (IV), optionally in the presence of a base and a solvent;
• wherein,
• R9 is selected from the group consisting of CI, Br and C1-C4 alkoxy;
• R10 is selected from the group consisting of cyano, CH2X, CH2—(C═O)—ORa, COORa, C(O)Rc and CRd═NRe;
• Ra is selected from the group consisting of hydrogen and C1-C4-alkyl,
• Rc is selected from the group consisting of N(Ra)2 and two Ra together with the atoms to which they are attached or together with further atoms selected from the group consisting of C, N, O, S and optionally including 1 to 3 ring members selected from the group consisting of C(═O), C(═S), S(O)m and SiR′2 may form a five to six membered non-aromatic ring;
• —Rd is selected from the groups consisting of hydrogen, C1-C4-alkyl, (C═O)—Ra, COORa, CON(Ra)2 and phenyl;
• Re is selected from the groups consisting of hydroxy and C1-C4 alkoxy;
• X represents halogen;
• b) reacting the compound of formula (IV) with an acid to obtain isatin of formula (V), optionally in the presence of a solvent;
• c) oxidizing the isatin of formula (V) to obtain isatoic anhydride of formula (VI) in presence of a oxidizing agent and a catalyst, optionally in the presence of a solvent;
• or
• hydrolyzing the isatin of formula (V) to obtain an anthranilic acid of formula (Vlla) in presence of a hydrolysisng agent, optionally in the presence of a solvent;
• and
• d) reacting the compound of formula (VI) with a compound of formula (VIII), to obtain a compound of formula (VII), optionally in the presence of an acid and a solvent;
• as shown in the following scheme: