Reaction Of K2PtCl4 Research Articles

Antitumoraktive Platin(II)‐Komplexe Mit Substituierten 2‐Aminomethylpyridin‐Liganden

Reaction of K2PtCl4 with the substituted 2-aminomethylpyridines 9, 14, and 22 affords the corresponding dichloroplatinum(II) complexes 3-5. Compounds 3 and 22 show remarkable relative binding affinities for the estrogen receptor. Towards the hormone-independent P388-tumor of the CD2F1-mouse the platinum(II) complexes 4 and 5 are weakly active, complex 3 is inactive. Towards the hormone-independent MDA-MB 231-cell line, compounds 3-5, 9, 14, and 22 exhibit no significant antitumor activity. Towards the hormone-dependent MCF-7 cell line, compounds 3-5, 9, 14 show weak antitumor activity, whereas compound 22 exhibits strong inhibition.

Platinum(II) and platinum(IV) complexes of 2-amino-4, 6-dimethylpyrimidine

Platinum(II) and platinum(IV) complexes of 2-amino-4, 6-dimethylpyrimidine, ADMPY, have been prepared. Solids of formula Pt(ADMPYH+)Cl3, Pt(ADMPY)2Cl4 and Pt(ADMPY)2Cl4·2HCl have been isolated and characterized by elemental analyses in conjuction with i.r. and n.m.r. spectra. A paramagnetic tan to reddishbrown complex has been reproducibly prepared from the direct reaction of K2PtCl4 and ADMPY at pH 6.

ChemInform Abstract: Synthesis and Antitumor Activity of cis‐Dichloroplatinum Complexes Coordinating Nitrogen Cyclic or Sulfur Compounds.

cis-Dichloroplatinum complexes of nitrogen cyclic compounds and sulfur-containing compounds were synthesized through the reaction of K2PtCl4 with the corresponding ligands in water or an interfacial layer between water and an organic solvent. The effect of substituents of pyridine derivatives on the synthesis of the cis-platinum complexes depended greatly on their position. The coordination of 2-substituted pyridines required a long reaction time and the yields were low. That of 3- or 4-substituted pyridines proceeded smoothly in high yields. The complexes coordinating dimethyl- or trimethyl-substituted pyridines were obtained in low yields, but a methyl group at the para position increased the coordination activity of pyridines. The reactivity of other nitrogen cyclic compounds depended greatly on their structures and no clear correlation between structure and reactivity was observed. In some cases, polynuclear or unidentified complexes were formed. Sulfurcontaining compounds reacted smoothly in high yields.Three synthesized cis-dichloroplatinum(II) complexes coordinating di(3-methylpyridine), di(quinoline) and di(isoquinoline) and a polynuclear platinum piperidine complex (Pt4Cl5(OH)3-(C5H11N)6·3H2O) had high antitumor activities against Sarcoma 180 ascites in female ICR/CRJ mice. The required platinum weight of these effective complexes for antitumor activity was in the range of 23-94 mg/kg in mice compared with 5 mg/kg in the case of cis-dichlorodiammineplatinum.

ChemInform Abstract: Synthesis and Antitumor Activity of a Novel Diplatinum Complex of the Binucleating Naphthazarinato Ligand.

AbstractThe Complex (I) is obtained by a 2:1 reaction of K2PtCl4 with naphthazarine in the presence of an excess of ammonia, and characterized by IR and electronic spectral data.

Synthesis and antitumor activity of cis-dichloroplatinum complexes coordinating nitrogen cyclic or sulfur compounds.

cis-Dichloroplatinum complexes of nitrogen cyclic compounds and sulfur-containing compounds were synthesized through the reaction of K2PtCl4 with the corresponding ligands in water or an interfacial layer between water and an organic solvent. The effect of substituents of pyridine derivatives on the synthesis of the cis-platinum complexes depended greatly on their position. The coordination of 2-substituted pyridines required a long reaction time and the yields were low. That of 3- or 4-substituted pyridines proceeded smoothly in high yields. The complexes coordinating dimethyl- or trimethyl-substituted pyridines were obtained in low yields, but a methyl group at the para position increased the coordination activity of pyridines. The reactivity of other nitrogen cyclic compounds depended greatly on their structures and no clear correlation between structure and reactivity was observed. In some cases, polynuclear or unidentified complexes were formed. Sulfurcontaining compounds reacted smoothly in high yields.Three synthesized cis-dichloroplatinum(II) complexes coordinating di(3-methylpyridine), di(quinoline) and di(isoquinoline) and a polynuclear platinum piperidine complex (Pt4Cl5(OH)3-(C5H11N)6·3H2O) had high antitumor activities against Sarcoma 180 ascites in female ICR/CRJ mice. The required platinum weight of these effective complexes for antitumor activity was in the range of 23-94 mg/kg in mice compared with 5 mg/kg in the case of cis-dichlorodiammineplatinum.

Formation of the ?-acetonyl Pt(IV) complex in the reaction of iodoacetone with PtCl 4 2? in aqueous solution

The reaction of K2PtCl4 with iodoacetone in aqueous solution at about 20‡C gives the σ-acetonyl Pt(IV) complex which is more stable to the action of nucleophilic reagents than the analogous methyl and ethyl complexes.

Synthesis of cis- and trans-platinum compounds with pyrimidine and crystal structures of trans-[Pt(pyrimidine)2X2] where X = Cl and Br

cis- and trans-[Pt(pm)2X2] where pm = pyrimidine and X = Cl, Br, have been synthesized. The cis-compounds were isolated from the reaction of K2PtCl4 and pm in water, while the trans-isomers were obtained by isomerization of cis-[Pt(pm2X2] in DMF in the presence of pm.The crystal structures of the two compounds trans-[Pt(pm)2X2] have been determined by X-ray diffraction. The two compounds (X = Br and Cl) are isostructural. The crystals belong to the monoclinic P21/c space group. The cell parameters are a = 4.787(3), b = 14.257(7), c = 8.503(3) Å and β = 99.33(4)° when X = Cl and a = 4.826(3), b = 14.822(5), c = 8.516(5) Å and β = 101.26(4)° when X = Br. The platinum atom is located on a centre of symmetry at the origin and Z = 2. The residual factors are R = 0.029 and Rw = 0.036 (X = Cl) and R = 0.036 and Rw = 0.035 (X = Br).

Cis- and trans-Platinum compounds of substituted pyrimidines and their products from thiourea in Kurnakov's reaction

cis- and trans-[Pt(pm)2X2] (where pm = 2-aminopyrimidine, 4-phenylpyrimidine, 4-methyl-pyrimidine and X = Cl, Br) were prepared and characterized. The cis compounds were isolated from the reaction of K2PtCl4 and pm in water, while trans-[Pt(pm)2X2] was obtained by isomerization of cis-[Pt(pm)2X2] in dimethylsulfoxide. The cis- and trans-isomers react with thiourea (tu) to give different products (Kurnakov's test).[Formula: see text]The complexes trans-[Pt(pm)2(tu)2]X2 were isolated and characterized.

Reactions of K2PtCl4 with pyridine derivatives in dimethylformamide and synthesis of potassium trichloro(pyridine)platinum(II)

The reactions of K2PtCl4 with pyridine derivatives L (L = py = pyridine, pic = picoline, and lut = lutidine) were studied in dimethylformamide (DMF).[Formula: see text]The complexes (1) were isolated and the yield decreased with the order, 2,4-lut = 2-pic > 2,6-lut > 4-pic = py, which can be correlated to the steric hindrance of the ortho methyl groups. The compounds (2) can be converted to the compounds (3), the free ligand acting as catalyst and (3) is the final product of the above reactions. The compounds (3) can also be obtained from a DMF solution of [Pt(L)4]Cl2 (L = py) at room temperature. A comparison of the above reactions in water and in DMF was also made.

Spécificité de l'interaction DNA‐platine dosage du platine, pH métrie

AbstractInteraction between the sodium salt of a DNA extracted from salmon sperm (41% GC) with [Pt(NH3)4]Cl2, [Pt(NH2(CH2)2NH(CH2)2NH2Cl]Cl, cis‐Pt(NH2(CH2)2NH2)Cl2, cis‐Pt(NH3)2Cl2, trans‐Pt(NH3)2Cl2, K[Pt(C2H4)Cl3], and K2[PtCl4) indicates at least three types of complexation. A correlation is found between the change of pH and the number of platinum atoms fixed per (AT + GC) unit. The first binding site is located on the G‐C pairs (guanine–cytosine), most likely the N‐7(G) site, as it was shown in a previous study of the guanosine‐platinum salts. The fixation of the second platinum atom by the pair (AT + GC) takes place with liberation of protons. In the case of the complexes cis‐Pt(NH2(CH2)2NH2)Cl2, cis‐Pt(NH3)2Cl2, and trans‐Pt(NH3)2Cl2 the second interaction seems to involve simultaneously the N‐7(A) and the N‐1(G) and N‐3(C) sites. This latter intercrosslink between guanine and cytosine obviously liberates protons and the decrease of pH is related in this case to the trans effect of the platinum compounds. The first two platinum atoms in the reaction of K2PtCl4] or the Zeise salt, K[Pt(C2H4)Cl3] with DNA are fixed on the G‐C pairs. A maximum of six platinum atoms per (AT + GC) unit were fixed in this case. Preliminary experiments with a DNA extracted from bacteria Micrococcus lysodeikticus (72% GC) give similar results.

The Crystal Structure of cis-Dichloro(2,2′-oxydi-3-butene)platinum(II), PtCl2((CH2=CH—CH(CH3))2O)

The reaction of K2PtCl4 with CH3—CH=CH—CH2—OH yields the complex cis-[PtCl2((CH2=CH—CH(CH3))2O)]. The crystals are triclinic, space group [Formula: see text], a = 9.420(2) Å, b = 8.359(4) Å, c = 7.837(4) Å, α = 91.10(4)°, β = 62.13(4)°, γ = 80.80(5)°, and Z = 2. The structure, solved by standard methods, has been refined anisotropically by full matrix least-squares methods to a R factor of 0.052 by use of 2441 independent observed reflections. The complex is a monomer, where both double bonds of the diolefin ether are coordinated to the platinum atom as in Zeise's salt. The usual square planar coordination of platinum(II) is completed by two chlorine atoms. The (=CH2) groups of both double bonds are found on the same side of the coordination plane. Various possible conformations of the coordinated ligand in the complex are discussed.

Platinum and iron complexes of pentamethylcyclopentadiene and related ligands

Hexamethylbicyclo[2,2,0]hexa-2,5-diene reacts with [Pt(C2H4)Cl2]2 to give dichloro(hexamethylbicyclo[2,2,0]hexa-2,5-diene)platinum and with K2PtCl4, under acidic conditions, to give dichloro(pentamethylcyclopentadiene)platinum, (III). The latter complex is also obtained from reaction of K2PtCl4 with C5Me5CHXMe (X = H, Cl, OMe, or OEt) in acidic methanol. A mechanism is suggested for these reactions. A mixture of (III) and dichloro(pentamethyl-5-vinylcyclopentadiene)platinum, (VI), is obtained on reaction of C5Me5CHXMe with [Pt(C2H4)Cl2]2 in aprotic solvents. Complex (VI) is the sole product from a similar reaction with pentamethyl-5-vinylcyclopentadiene, and an analogous complex is obtained from 5-ethylpentamethylcyclopentadiene. The stereochemistries of these complexes have been determined. The pentamethylvinylcyclopentadiene complex (vinyl endo-) undergoes an unusual hydrogen-catalysed reaction to give the isomeric complex with vinyl exo- to the metal. Reaction of (III) with Fe3(CO)12 gave [Fe(C5Me5)(CO)2]2 and endo-H Fe(C5Me5H)(CO)3.