Quinaldine based semisquaraines and squaraine dyes, process for preparation thereof and use thereof

A process for the preparation of a semisquaraine of the formula 1

• wherein, X=H, I, Br, NO2, CN, COOH, SO3H or OR1, wherein R1=H, alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, cholic acid, cholesterol, sugar, amino acids or peptides, wherein Y=H, I, or Br, wherein, Z=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl or OR1, wherein R2=alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, alkyl sulphonic acids and acid chlorides having from 1 to 6 carbon atoms, said process comprising reacting quinaldinium salt and squaric acid in a mixture of benzene and n-butanol under stirring, removing the solvent and purifying the residue obtained to obtain compound of formula 1.

Quinaldine based symmetrical squaraine dye of formula 2 below or pharmaceutically acceptable salts thereof

• wherein, X=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl or OR1, wherein, R1=H, alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, cholic acid, cholesterol, sugar, amino acids or peptides, wherein, Y=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl or OR1, wherein R2=alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, alkyl sulphonic acids and acid chlorides having from 1 to 6 carbon atoms.

Process for the preparation of a quinalidine based symmetrical squaraine dye of formula 2

• wherein, X=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl or OR1, wherein, R1=H, alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, cholic acid, cholesterol, sugar, amino acids or peptides, wherein, Y=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl or OR1, wherein R2=alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, alkyl sulphonic acids and acid chlorides having from 1 to 6 carbon atoms, said process comprising reacting a quinaldinium salt and squaric acid in a solution of benzene and n-butanol with stirring, removing said solvent and then purifying the residue so obtained to obtain the squaraine dye of formula 2.

A quinaldine based asymmetrical squaraine dye of formula 3 and pharmaceutically acceptable derivatives thereof

• wherein, X=OR1, wherein, R1=H, alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, cholic acid, cholesterol, sugar, amino acids or peptides, wherein Y=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl or OR1, wherein Q=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl, wherein Z=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl, wherein R2=alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, alkyl sulphonic acids and acid chlorides having from 1 to 6 carbon atoms.

A process for the preparation of a quinaldine based asymmetrical squaraine dye of formula 3

• wherein, X=OR1, wherein, R1=H, alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, cholic acid, cholesterol, sugar, amino acids or peptides, wherein Y=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl or OR1, wherein Q=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl, wherein Z=H, I, Br, NO2, CN, COOH, SO3H, SO2Cl, wherein R2=alkyl groups having from 1 to 6 carbon atoms, glycols having from 2 to 4 ethylene groups, alkyl sulphonic acids and acid chlorides having from 1 to 6 carbon atoms, said process comprising heating a quinaldine based semisquaraine of formula 1 and quinaldinium salts substituted with halogen atoms at 6-position in a mixture of benzene and n-butanol, removing the solvent to obtain a residue which on purification provides compound of formula 3.

Use of compound of formula 1 as a photosensitizer in photodynamic treatment of cancer and other related diseases.

Use of compound of formula 1 as a near infrared fluorescent sensor for diagnosis of cancer.

Use of compound of formula 1 as a sensitizer in sterilization of fluids such as water.

Use of compound of formula 2 as a photosensitizer in photodynamic treatment of cancer and other related diseases.

Use of compound of formula 2 as a near infrared fluorescent sensor for diagnosis of cancer.

Use of compound of formula 2 as a sensitizer in sterilization of fluids such as water.

Use of compound of formula 3 as a photosensitizer in photodynamic treatment of cancer and other related diseases.

Use of compound of formula 3 as a near infrared fluorescent sensor for diagnosis of cancer.

Use of compound of formula 3 as a sensitizer in sterilization of fluids such as water.