# US 4,396,588 A · Preparation of cis-diamminediaquaplatinum(II) nitrate

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- Number: US 4,396,588 A
- Document ID: US4396588A
- Status: Granted
- Kind: A
- Application number: 06/323,889
- Filed: 1981-11-23
- Granted: 1983-08-02
- Earliest claimed: 1979-08-16
- Assignees: MPD Technology Corporation
- Inventors: Richard N. Rhoda; Jeffrey N. Crosby
- Web page: https://patentgrep.com/patent/US4396588A

## CPC

- C01G 5/02: Halides
- A61K 33/243: Platinum; Compounds thereof
- C01G 55/00: Compounds of ruthenium, rhodium, palladium, osmium, iridium, or platinum
- C01G 55/002: {Compounds containing ruthenium, rhodium, palladium, osmium, iridium or platinum, with or without oxygen or hydrogen, and containing two or more other elements (C01G55/007 takes precedence)}
- C01P 2006/60: Optical properties, e.g. expressed in CIELAB-values
- C01G: COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts or peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium, or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds containing nitrogen, other non-metals and metal C01B21/082}; metal amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanamide C01C3/16; thiocyanates C01C3/20)
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS

## Abstract

A process is provided for preparing cis-[Pt(NH.sub.2).sub.3 (H.sub.2 O).sub.2 ](NO.sub.3).sub.2 by a process comprising preparing cis-Pt(NH.sub.3).sub.2 I.sub.2 from K.sub.2 PtI.sub.4 under controlled conditions of temperature and pH and converting the resultant cis-Pt(NH.sub.3).sub.2 I.sub.2 to the diaqua complex with AgNO.sub.3 under controlled conditions.

## Claims

### Claim 1

A process for preparing a cis-diamminediiodoplatinum(II) complex of high purity and in high yield from potassium tetraiodoplatinum(II) by a method comprising adding an aqueous solution of ammonium hydroxide to an aqueous dispersion of potassium tetraiodoplatinum(II), said tetraiodo compound having the formula K.sub.2 PtI.sub.4, under a controlled gradually rising temperature profile while controlling the ammonium hydroxide addition so that the pH does not exceed about 7.5, washing and drying the resultant precipitated cis-Pt(NH.sub.3).sub.2 I.sub.2, slowly adding the washed and dried cis-Pt(NH.sub.3).sub.2 I.sub.2 to an aqueous solution of AgNO.sub.3 at room temperature and with rapid stirring, warming the silver-containing mixture to a maximum temperature of about 50.degree. C. and maintaining the temperature of about 50.degree. C. for a period of time sufficient substantially to complete the reaction, then cooling the resultant silver-containing reaction mixture to room temperature to form a solution containing cis-[Pt(NH.sub.3).sub.2 (H.sub.2 O).sub.2 ](NO.sub.3).sub.2 and a AgI precipitate and separating the precipitated AgI from the solution containing cis-[Pt(NH.sub.3).sub.2 (H.sub.2 O).sub.2 ](NO.sub.3).sub.2.

### Claim 2 (depends on 1)

A process according to claim 1, wherein the AgNO.sub.3 reagent is used in an amount slightly below stoichiometric for complete conversion of cis-Pt(NH.sub.3).sub.2 I.sub.2, and after separation of the AgI, to the remaining solution is added MCl (where M=K or Na) in a small but effective amount for precipitating Ag.sup.+, and precipitated AgCl is separated from the solution, thereby forming a purified solution of cis-[Pt(NH.sub.3).sub.2 (H.sub.2 O).sub.2 ](NO.sub.3).sub.2 with minimized Ag.sup.+ content.

### Claim 3 (depends on 1)

A process according to claim 1, wherein the Ag.sup.+ in solution containing cis-[Pt(NH.sub.3).sub.2 (H.sub.2 O).sub.2 ](NO.sub.3).sub.2 is monitored with a silver/silver chloride electrode to minimize the Ag.sup.+ in solution.

### Claim 4

A process for preparing cis-[Pt(NH.sub.3).sub.2 (H.sub.2 O).sub.2 ](NO.sub.3).sub.2 of high purity and in high yield comprising: slowly adding a concentrated aqueous solution of KCl to a solution of chloroplatinic acid at a temperature of about 50.degree. to about 60.degree. C., to precipitate K.sub.2 PtCl.sub.6, cooling the solution to about 0.degree. C. and permitting it to stand to ensure complete precipitation, separating and washing the K.sub.2 PtCl.sub.6 precipitate, adding dropwise and at room temperature to an aqueous dispersion of the washed K.sub.2 PtCl.sub.6 an aqueous solution of N.sub.2 H.sub.4.2HCl in excess of the stoichiometric amount, warming the resultant mixture to about 60.degree. C. until the dispersed K.sub.2 PtCl.sub.6 has dissolved, thereafter heating the solution stepwise up to about 85.degree. C. thereby forming K.sub.2 PtCl.sub.4 in solution, adding an aqueous solution of KI to the aqueous solution of K.sub.2 PtCl.sub.4 to convert said K.sub.2 PtCl.sub.4 to the corresponding K.sub.2 PtCl.sub.4 at a temperature of about 40.degree. C. and maintaining the solution at a temperature to about 40.degree. C. to about 85.degree. C. to maximize conversion to K.sub.2 PtI.sub.4 to a water dispersion of said K.sub.2 PtI.sub.4, at a temperature of about 40.degree. C. adding a dilute solution of NH.sub.4 OH slowly with stirring and with pH control so that the pH of 7.5 is not exceeded during the addition until the K.sub.2 PtI.sub.4 dispersion dissolves, maintaining the resultant solution at a temperature of about 40.degree. C. to about 60.degree. C. and adding additional NH.sub.4 OH to a pH of about 7.5, then cooling the pH-adjusted solution to room temperature to precipitate cis-Pt(NH.sub.3).sub.2 I.sub.2, separating and washing the precipitated cis-Pt(NH.sub.3).sub.2 I.sub.2, adding the washed cis-Pt(NH.sub.3).sub.2 I.sub.2 to an aqueous solution of AgNO.sub.3 while stirring and at room temperature, said AgNO.sub.3 being present in a controlled amount to react with the cis-Pt(NH.sub.3).sub.2 I.sub.2 with minimum unreacted Ag, warming the silver-containing mixture to about 50.degree. C. to ensure complete reaction and then cooling the resultant silver-containing mixture thereby forming a AgI precipitate and an aqueous solution containing cis-[Pt(NH.sub.3).sub.2 (H.sub.2 O).sub.2 ](NO.sub.3).sub.2.