Indian Journal of Chemistry Vol. 40B, December 21 , pp. 1236-1238 Note Synthesis of phthalocyanines crosswise- substituted with two alkylsulfanyl and two crown-ether M Salih Aglrta� l , Mehmet Sonmez* 2 , Mehmet Kandaz 3 & O zer Bekaroglu 4 I .Department of Chemistry, Faculty of Arts and Sciences, Kafkas University, 360 Kars-Turkey 2 Department of Chemistry, Faculty of Arts and Sciences,Ylizlincli Y.I University, 65080 Van- Turkey 3 ·Department of Chemistry, Faculty of Arts and Sciences, Sakarya University, 54100 Sakarya-Turkey 4 Department of Chemistry, Technical University of Istanbul, 80626 Maslak Istanbul-Turkey Received 30 March 2000; accepted (revised) J 2 December 2000 Crosswise-substutited phthalocyanines with two nitro and two dodecylsulfanyl groups are synthesized by a 1: 1 condensation of I ,3-dihydro- 1 ,3-di imino-6-(n-dodecylsulfanyl) isoimino indo- lenine with 6-nitro- l ,3,3-trichloroisoindolenine in the presence of sodium methoxide, hydroquinone and triethylamine. Nitro sub- stituents are reduced to amines by sodium sulf ide and condensa- tion of the amino groups with benzo-1 5-crown-5-aldehyde results in a new Pc with two benzo- 1 5-crown-5-imino substituents. The compounds have been characterized by elemental analyses, UVIVis and IR spectroscopy. Phthalocyanines, in particular their readily soluble peripherally substituted derivatives, possess a wide range of chemical and physical properties that make them interesting building blocks for a number of ap- plications and new materials I. In contrast to the ther- mal stability of phthalocyanines (Pc), their solubility in common solvents causes difficulties for many ap- plications. Peripheral substitution of Pcs with long alkyl chains or bulky groups enable one to overcome these diffuculties 2 • The consequence of cyclotet- ramerization of substituted phthalonitrile derivatives is normally Pcs with some substituents on all four benzenoid groups I . Various strategies have been promulgated in efforts to achieve products with dif- ferent substituents on each of the benzo units. The use of a mixture of phthalonitrile derivatives in the syn- thesis can be considered as a first approximation, but then the result is a statistical mixture of Pc derivative, which cannot be isolated in any practical way, not even sometimes by chromatographic methods. Pub- lished routes specifically designed include reaction of a phthalonitrile derivative bound to an insoluble polymer with a large excess of another phthalonitrile derivative 3 . Although the cross condensation of a 1,3- diiminoisoindolenine derivative with 1,3,3- tricholoroisoindolenine has been reported as an inter- esting method to obtain Pcs subtituted with two dif- ferent groups 4 , only a few further application of this new method has been encountered. In the present work, soluble phthalocyanines peripherally substi- tuted with two amino and two alkylsulfanyl groups located crosswise have been synthesized and their reactivity has been exemplified through the formation of a Schiffs base with benzo-15-crown-5 aldehyde. Results and Discussion The synthesis of the crosswiseisubstituted Pcs 6- 7,9 is shown in the Scheme I. The starting point for both of the precursors is 4-nitrophthalimide. It is con- verted into 4-nitrophthalonitrile 4 and subsequent nu- cleophilic displacement of the nitro group with Il-dodecylmercaptan gives 4-dodecylsulfanylphthalo- nitrile s , 6 3, which is reacted with ammonia in the pres- ence of sodium methoxide to obtain the isoi minoin- doline derivative 6 5 as the first precursor. The second precursor, namely 6-nitro- l,3,3-trichloroisoindolenine 4, is prepared by chlorination of 4-nitrophthaliide with PCIs in o-dichl orobenzene 4 , 6 . Cyclotetrameriza- tion of these two reactants in a 1 : 1 rati.o is accom- plished in THF in the presence of triethylamine and sodium methoxide as the base and hydroquinone as the reductant 6 . An interesting point to be noted about the above sequence concerns the reductive coupling of the chloro 4 with the isoiminoindolenine derivative 5. Reproducible yields of the Pcs could not be ob- tained unless the above acid acceptor and hydrogen donor are present. After purification, the yields of these compounds are found to be rather higher than literature. Peripheral nitro substituents on the Pc core of fer a number of possibilities to obtain reactive binding sites, such as reduction to an amine. For this purpose, sodium sulfide is preferred as the reductant as in the case of tetranitro-substituted Pcs ? In order to demon- strate the reactivity of amino groups in diaino- didodecyl-sulfanyl Pc 7, its condensation with benzo- 15-crown-5 aldehyde 6 • 8 was carried out to obtain a