[E004]

Vladimir N. Bulavka

“Slavich Company”, Mendeleev sq. 2, Pereslavl-Zalesskiy, Yaroslavl region,

152025, Russian Federation. E-mail: nifti@slavich.botik.ru

Abstract: Microwave irradiation of potassium phthalimide, potassium phenylacetate, magnesium oxide and urea resulted in formation of phthalocyanine, meso-tetraphenyltetrabenzoporphine, and four (meso-phenyl, aza)tetrabenzoporphine magnesium complexes, separated by extraction and chromatography on silica gel column.

Keywords: Microwaves, magnesium phthalocyanine, magnesium azatetrabenzoporphines, magnesium meso-penyltetrabenzoporphines.

The synthesis of phthalocyanine metal complexes in the industrial microwave installations by periodic (0.1 - 1.0 mol) or continuous-type (5 kg/hr) processes [1] or in the laboratory commercial microwave oven including rotation evaporator modified oven [2] are alredy described. Earlier, we have described meso-tetraphenyltetrabenzoporphine metal complexes synthesis under microwave irradiation [3].

Here we present synthesis and separation of magnesium phthalocyanine (I), 6,13,20-triaza-27-phenyl-29H,31H-tetrabenzo[b,g,l,q]porphine (II), magnesium 6,13-diaza-20,27-diphenyl-29H,31H-tetrabenzo[b,g,l,q]porphine (III), magnesium 6,20-diaza-13,27-diphenyl-29H,31H-tetrabenzo[b,g,l,q]porphine (IV), magnesium 6-aza-13,20,27-triphenyl-29H,31H-ltetrabenzo[b,g,l,q]porphine (V), and magnesium 6,13,20,27-tetraphenyl-29H,31H-tetrabenzo[b,g,l,q]porphine (VI) mixture obtained under irradiation in rotation evaporator modified microwave oven. Above modification served in our investigation for stirring of reaction mixture and nitrogen atmosphere formation in reaction vessel.

Earlier, synthesis of similar mixture from diiminoisoindoline, sodium phenylacetate, and magnesium oxide after 2 hr fusion at 280° C and chromatographic separation of II - V mixture on alumina was reported, however, I and VI formation and isolation were not mentioned [4].

Synthesis of above magnesium complexes mixture in microwave oven was carried out by 0.5 hr fusion 0.01mols of dry potassium phthalimide, potassium phenylacetate, urea, and magnesium oxide mixture. Thus was obtained mixture of I, II, III, IV, V, and VI. From this mixture I [2, 5] (65%) was separated as unsoluble precipitate after extraction with water and chloroform. Chromatography of chloroform extract on silica gel (benzene - chloroform) afforded successively VI [6] (3%), V [4, 7] (9%), IV [4, 8] (4%), III [4, 9] (4%), and II [4, 10] (8%).

Above: the oven (“Elektronika”, 500W) with rotation evaporator mechanism, the door closed (left) and opened (right); below: the fully equipped installation during experiment (1 l round-bottom reaction flask), the door closed before MW irradiation (left) and opened after end of reaction (right).

Acknowledgement. The modification of microwave oven made by Victor N. Gladkov is gratefully acknowleged.

References

1. E. A. Filippov, V. V. Shatalov, V. A. Serdenko, K. V. Derevlev, A. N. Evdokimov, V. A. Dushechkin, T. S. Dakalova, M. V. Kazankov, V. A. Smrchek, I. N. Sinitsyna, Ya. N. Tayakin, L. Yu. Sladkov, E. A. Luk'yanets, V. M. Derkacheva. Apparatus and process using microwave radiation for preparing metal phthalocyanines. RU 2045555 (C09B47/06), 10.10.1995, appl. 93042468/04, 30.08.1993. Izobreteniya 1995, (28), 183 (Russian). (Chem. Abstr. 1996, 124(24), 319684g).

2. D. Villemin, M. Hammadi, M. Hachemi, N. Bar. Applications of microwave in organic synthesis: An improved one-step synthesis of metallophthalocyanines and a new modified microwave oven for dry reactions. Molecules 2001, 6(10), 831-844, - printed, and Internet version http://www.mdpi.org/molecules.

3. V. N. Bulavka. Synthesis of 6,13,20,27-tetraphenyl-29H,31H-tetrabenzo[b,g,l,q]porphine coordination metal coplexes under irradiation in modified microwave oven. XXI International Chugaev’s Conference on Coordination Chemistry. (Ukraine, Kyiv, 10-13.06.2003). Theses of Reports. Kyiv, 2003, p. 210. (Ukrainian).

4. N. E. Galanin, E. V. Kudrik, G. P. Shaposhnikov. Synthesis and properties of meso-phenylsubstituted tetrabenzoazaporphines magnesium complexes. Zh. Org. Khim. 2002, 38(8), 1251-1254. (Russian, English version: Russ. J. Org Chem. 2002, 38(8)).

5. C₃₂H₁₆MgN₈, UV-VIS, l _max (nm) (2,4-Cl₂C₆H₃CH₃): 584, 612, 645, 678.

6. C₆₀H₃₆MgN₄, UV-VIS, l _max (nm) (ClCH₂CH₂Cl): 462, 464(sh.), 590, 640.

7. C₅₃H₃₁MgN₅, UV-VIS, l _max (nm) (C₆H₅CH₃): 443, 607, 641, 658.

8. C₄₅H₂₆MgN₆, UV-VIS, l _max (nm) (C₆H₅CH₃): 429, 592, 652, 679.

9. C₄₅H₂₆MgN₆, UV-VIS, l _max (nm) (C₆H₅CH₃): 428, 597, 653, 677.

10. C₃₉H₂₁MgN₇, UV-VIS, l _max (nm) (C₆H₅CH₃): 431, 465, 609, 655, 675.