Dichroic azo-azomethine dyes for liquid crystal compositions

A process for preparing a compound of formula (A)

• wherein
• Ar1 is a residue selected from the group consisting of
• Ar2 and Ar3 are independently of one another and at each occurrence selected from
• Ar4 is a residue
• of C2-C10-heteroaryl, C2-C10-heteroaryl substituted with C1-C12-alkyl, C1-C12-alkoxy, C1-C12-alkylthio, OH, halogen, C1-C4-haloalkyl, NR12R13, CO2R14, COR15, SO2R16, NO2 or CN;
• X is C1-C6-haloalkyl, CN, COOR17,
• Y is H, C1-C12-alkyl;
• C1-C12-alkyl substituted with OH or NH2 and/or interrupted with NR23, O or S;
• C1-C12-haloalkyl, C7-C12-aralkyl;
• NR24R25, halogen, CN, OH, C1-C12-alkoxy;
• C2-C12-alkoxy interrupted with O;
• C1-C12-alkylthio;
• COOR26, C6-C12-aryl;
• C6-C12-aryl substituted with C1-C12-alkyl, C1-C12-alkoxy, C1-C12-alkylthio, CN, halogen, OH or NR27R28, C2-C10-heteroaryl, C2-C10-heteroaryl substituted with C1-C12-alkyl, C1-C12-alkoxy, C1-C12-alkylthio, OH, halogen, CN or NR29R30;
• C3-C18-cycloalkyl, or C3-C18-cycloalkyl substituted with C1-C12-haloalkyl, halogen, CN, OH, C1-C12-alkoxy, C1-C12-alkylthio or NR31R32 and/or interrupted by one or more O;
• or Y and one adjacent H form together a group
• or a 5 to 7-membered heterocyclic ring containing one or two Q,
• Q is NR33, O or S;
• said group
• or heterocyclic ring is unsubstituted or substituted with C1-C4alkyl;
• R1 is C1-C12-alkyl, C1-C12-haloalkyl, halogen, CN, C1-C12-alkoxy or C2-C12-alkoxy interrupted with O;
• R2, R3, R4, R5, R6, and R7 are independently of one another and at each occurrence selected from H, halogen, OCF3, NO2, CN, formyl, COOR34, COR35, SO2R36, CONR37R38, C1-C12-alkyl;
• C1-C12-alkyl substituted with halogen or CN;
• C1-C12-alkoxy;
• C2-C12-alkoxy interrupted with O;
• C3-C12-cycloalkyl;
• C3-C12-cycloalkyl substituted with halogen or CN and/or interrupted by one or more O;
• phenyl;
• or phenyl substituted with halogen, CN, C1-C8-alkyl or C1-C8-haloalkyl;
• or R2 and R3, or R6 and R7 together are C3-C4-alkylene or form a benzoanellated ring, said alkylene or benzoanellated ring is unsubstituted or substituted with C1-C4-alkyl, CN, C1-C4-alkoxy, NO2, halogen, or SO2R39;
• R8 and R9 are independently of one another and at each occurrence selected from C1-C4-alkyl, C1-C4-haloalkyl, halogen, CN or C1-C4-alkoxy;
• R10 is at each occurrence selected from C1-C12-alkyl, C1-C4-haloalkyl, C1-C12-alkoxy, OH, halogen or CN;
• R11 is at each occurrence C1-C4-alkyl;
• R14, R15, R16, R17, R26, R34, R35, R36, R39 and R40 are independently of one another C1-C12-alkyl;
• C1-C12-alkyl substituted with CN or OH;
• C1-C12-haloalkyl;
• C3-C18-cycloalkyl, C3-C12-cycloalkyl substituted with C1-C12-haloalkyl, CN, OH or halogen and/or interrupted by one or more O;
• C6-C12-aryl, C6-C12-aryl substituted with halogen, CN, OH, C1-C12-alkyl or C1-C12-haloalkyl;
• phenylene-C3-C18-cycloalkyl;
• phenylene-C3-C18-cycloalkyl substituted with halogen, CN or OH;
• C3-C12-cycloalkylene-phenyl;
• or C3-C12-cycloalkylene-phenyl substituted with C1-C12-alkyl, C1-C12-haloalkyl, halogen, CN or OH;
• R12, R13, R24, R25, R27, R28, R29, R30, R31, R32, R37 or R38 are independently of one another H, C1-C12-alkyl;
• C3-C14-cycloalkyl;
• C6-C12-aryl;
• C6-C12-aryl substituted with halogen, CN, OH, C1-C12-alkyl or C1-C12-haloalkyl;
• phenylene-C3-C18-cycloalkyl;
• phenylene-C3-C18-cycloalkyl substituted with halogen, CN or OH;
• C3-C12-cycloalkylene-phenyl;
• or C3-C12-cycloalkylene-phenyl substituted with C1-C12-alkyl, C1-C12-haloalkyl, halogen, CN or OH;
• or R12 and R13, R24 and R25, R27 and R28, R29 and R30, R31 and R32, or R37 and R38 together are C2-C12-alkylene or C2-C12-alkylene interrupted by O, S and/or NR41;
• R23, R33 and R41 are independently of one another H, C1-C12-alkyl, C3-C12-cycloalkyl, phenyl or phenyl substituted with C1-C6-alkyl, or CN;
• m and n are independently of one another 0 or 1,
• with the proviso that the sum m+n≥1;
• s, t, u and v, are independently of one another 0, 1 or 2;
• and
• w is 0, 1, 2, 3 or 4
• the process comprising condensation of an amino-substituted azo compound of formula (A-A) and an aldehyde of formula (A-B):