Protoporphyrin IX dimethyl ester

In numerous synthetic studies,9" 6 100 it has been demonstrated that porphyrins react at the chromophore periphery in cycloaddition reactions, rearrangements, conjugative additions and substitution reactions to yield interesting porphyrin derivatives. Thus, metal-free protoporphyrin IX dimethyl ester reacts in Diels-Alder reactions108a b with dienophilcs like ethenetetra-carbonitrile and acetylenedicarboxylates at the diene structural parts to yield, according to the reaction conditions, the corresponding monoadducts 2 and 3 (see also Section 1.2.) and bisadducts 1 (see also Section 1.4.), respectively. 

Recently Cavaleiro et al. described an easy synthetic approach to glycoporphyrins from zinc(n) protoporphyrin-IX dimethyl ester 4 and O-allyl carbohydrate acetonides 5A-E (D-ribose (A), D-galactose (B), D-glucose (C), and two isomeric derivatives (D) and (E) of D-fructose) by cross-metathesis (Scheme 2).12 Two equivalents of each carbohydrate and the Grubbs catalyst were used, giving the carbohydrate derivatives 6 in a range of 74% to 93% yields. 

The Hill equation, often used by biochemists dealing with 1 1 equilibria, has recently been employed by Ibers and Stynes (32) to determine thermodynamic data for the sjretem 02 g) plus base-cobalt(II) protoporphyrin IX dimethyl ester in non-aqueous media. 

Using a typical poly (vinyl chloride) (PVC)-based membrane with different ionophores - Zn-bis(2,4,4-trimethylpen-tyl) dithiophosphinic acid complex [450], protoporphyrin IX dimethyl ester [451], porphyrin derivative [452] and hemato-porphyrin IX [453], tetra(2-aminophenyl) porphyrin [454], cryptands [455, 456], 12-crown-4 [457], benzo-substituted macro-cyclic diamide [458], 5,6,14,15-dibenzo-l, 4-dioxa-8,l 2, diazacyclopentadecane-5,14-diene [459], and (A-[(ethyl-l-pyrrolidinyl-2 -methyl) ] methoxy-2-sulfamoyl-5 -benza-mide [460] - the sensors for zinc ions were prepared and investigated. The armed macrocycle, 5,7,7,12,14,14-hexamethyl-1,4,8,11 -tetraazacyclo tetradeca-4,11 -diene dihydrogen perchlorate was used for the preparation of polystyrene-based Zn(II)-sensitive electrode [461]. 

Parallel studies were carried out cm the Co(ll)poiphyrin complexes91. We chose two porphyrin derivatives soluble in organic solvents protoporphyrin IX dimethyl-ester (PPME) 38, and tetraphenylporphyrin (TPP) 39. 

R1 = R2 = Et, mesoporphyrin dimethyl ester, H2MPDME R1 = R2 = H, deuteroporphyrin dimethyl ester, H2DPDME R1 = R2 = CH=CH2, protoporphyrin IX dimethyl ester, H2PPDME R1 = R2 = CH(OH)Me, hematoporphyrin dimethyl ester, H2HPDME... 

With DMAD, both the pyrrolidine 6199 and protoporphyrin IX dimethyl ester (63) behave as dienes and undergo Diels-Alder additions yielding 62 and 64, respectively.100,101... 

It was demonstrated some time ago that vinylic and cross-conjugated double bonds of protoporphyrin (IX) dimethyl ester (80a) constitute a diene system capable of undergoing Diels-Alder reactions with activated dieno-philes (68CC697). Isobacteriochlorins 81 and 82a were obtained in a reaction with dimethyl acetylenedicarboxylate (ACDE) and tetracyanoethene (TCNE), respectively (73JCS(PI)1424). 

Protoporphyrin IX dimethyl ester may be purchased (e.g., Porphyrin Products, Sigma, Strem) or prepared according to literature procedures.1 A convenient... 

A-methylimidazole with the corresponding protoporphyrin IX and protoporphyrin IX dimethyl ester complexes of chloroiron(III) and for the reaction of imidazole (Him) with TPPFeF and (PPDME)FeF. In the latter case, the first intermediate to form is, as before (equation 40), the six-coordinate high-spin PFe(HIm)F, and the second is PFe(HIm)F Him in which an external imidazole is hydrogen bonded to the fluoride. It has also been shown that reaction of hindered imidazoles such as 2-MeImH and 1,2-Me2lm with TPPFeCl introduces a steric strain with the porphyrin ring that causes about a factor of ten decrease in the formation constant, K (equation 40), and a factor of ten or more increase in the rate of chloride ion dissociation (equation 41). ... 

Figure 7.15 The typical arrangement of a porphyrin dimer is exemplified here with the crystal structure of protoporphyrin IX dimethyl ester. One pyrrole ring lies above the central cavity of the partner molecule.

Formation constants for the binding of axial ligands have been reported for many systems, for example pyridine with Fe" and Fe " tetraphenylporphyrin, other Fe porphyrins and Co" protoporphyrin IX dimethyl ester. Kinetic studies on the binding of axial ligands are also available. ... 

Janson, T. R., Katz, J. J. (1972). An Examination of the 220 MHz NMR Spectra of Meso-porphyrin IX Dimethyl Ester, Deuteroporphyrin IX Dimethyl Ester, and Protoporphyrin IX Dimethyl Ester, J. Magn. Resonance, 6 209. 

IR spectra of divalent-metal complexes of protoporphyrin IX dimethyl ester (PPIXDME, R,=Rj = R5 = R8 = CH3, R2=R4 = vinyl group, and R =R7= CHz—CH2—COOCH3) arfi reported by Boucher and Katz who noted several... 

Figure 14, Proton magnetic resonance spectrum at 100 MHz of fx oxo bis(protoporphyrin IX dimethyl ester iron(lIl)) in CDCI3 at 35°C...

QCM coated with thin films of metal complexes of protoporphyrin IX dimethyl ester (M-PPIX) deposited by electropolymerization was used to detect the vapors of triethylamine, acetic acid, ethanol, and toluene [52]. Poly-Ni(PPIX) shows larger sensitivity to toluene due to n-n interaction. 

M-PPIX Metal complexes of protoporphyrin IX dimethyl ester... 

Oxidation of protoporphyrin IX dimethyl ester with permanganate affords a mixture of the corresponding 2,4-diformyl derivative, chlorocnioro (20i), and... 

Other derivatives containing glycosidic and thioglycosidic moieties have also been prepared from protoporphyrin-IX [51]. Esterification of protopor-phyrin-IX 21 was performed with methanol containing 5% sulfuric acid [90]. The obtained dimethyl ester 22 was directly converted into isohemato-porphyrin dimethyl ester 27B (Scheme 1) treatment of protoporphyrin-IX dimethyl ester 22 with thaUium(III) nitrate in methanol gave the bis(2 -dimethoxyethyl)deuteroporphyrin which was then reacted with formic acid. 

Surprisingly, the electrooxidation of metal complexes of protoporphyrin-IX dimethyl ester, possibly via the vinyl groups, leads to the deposition of electroactive porphyrin films on the electrode surface [107-109], The electrochemical polymerization of pyrrole, thiophene and amine metal-substituted complexes is described in more detail in Section 6.3. 

Boucher and Katz (1967a) have investigated manganese protoporphyrin IX dimethyl ester complexes with anionic ligands F , Cl , Br , I", CN , and SCN. Elemental analyses and physical and spectral properties were consistent with the formulation, [Mn(III)porphyrin X]. Infrared spectra of the complexes, in the solid state and in nonpolar solvents, gave evidence for coordination of the anions to an axial position of the metal. Visible spectra also supported this conclusion. 

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