Phthalimidylazo dyes, processess for the preparation thereof and the use thereof

1. A dye of formula

wherein R 1 is C 1 –C 12 alkyl or —C n H 2n —(OCH 2 CH 2 ) m —OR 3 , n being a number from 2 to 8, m being a number from 0 to 4 and R 3 being C 1 –C 12 alkyl, C 6 –C 24 aryl or C 6 –C 24 aralkyl, R 2 is n-butyl,

X is halogen and

Y is hydrogen, chlorine or bromine.

2. A dye of formula (1) according to claim 1 , wherein R 1 is methyl, ethyl or n-butyl.

3. A dye of formula (1) according to claim 1 , wherein X is bromine.

4. A dye of formula (1) according to claim 1 , wherein Y is hydrogen.

5. A dye of formula (1a), (1b) or (1c)

6. A process for the preparation of a dye of formula (1d),

wherein R 1 is C 1 –C 12 alkyl or —C n H 2n —(OCH 2 CH 2 ) m —OR 3 , n being a number from 2 to 8, m being a number from 0 to 4 and R 3 being C 1 –C 12 alkyl, C 6 –C 24 aryl or C 6 –C 24 aralkyl,

R 2 is methyl, ethyl, n-propyl, n-butyl, 2-methoxyethvl or 2-ethoxyethyl,

X is halogen and

Y is hydrogen, chlorine or bromine

which comprises nitration of a phthalimide of formula

in the acid range, followed by alkylation of the resulting nitro compound and, by means of a reductive treatment, conversion into an intermediate of formula

halogenation of the intermediate of formula (3) in an acid medium and then diazotisation and coupling to a pyridone compound of formula (4)

7. A dye mixture comprising at least two structurally different dyes of formula (1) according to claim 1 .

8. A process for dyeing or printing semi-synthetic or synthetic hydrophobic fibre materials, in which process a dye of formula (1) according to claim 1 is applied to the said materials or incorporated into them.

9. A semi-synthetic or synthetic hydrophobic fibre material dyed or printed by the process according to claim 8 .

10. A method of dyeing or printing semi-synthetic or synthetic hydrophobic fibre materials, which comprises contacting said fiber materials with at least one dye of formula (1) according to claim 1 .