Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D231/00—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings
  • C07D231/02—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings
  • C07D231/10—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D231/14—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D231/18—One oxygen or sulfur atom
  • C07D231/20—One oxygen atom attached in position 3 or 5
  • C07D231/22—One oxygen atom attached in position 3 or 5 with aryl radicals attached to ring nitrogen atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D231/00—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings
  • C07D231/02—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings
  • C07D231/10—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D231/14—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D231/18—One oxygen or sulfur atom
  • C07D231/20—One oxygen atom attached in position 3 or 5

Definitions

• the present invention relates to a process for the preparation of N-substituted 3-hydroxypyrazoles of the formula I.
• R 1 for subst. Alkyl, alkenyl, alkynyl, cycloalkyl, aryl or heteroaryl and
• R 2 , R 3 for hydrogen, cyano, halogen and optionally subst.
• PCT / EP 96 / 02,891 describes the oxidation with atmospheric oxygen in organic solution in the presence of iron and copper salts.
• the oxidizing agent air creates explosive air / solvent vapor mixtures, which are questionable for safety reasons and make high demands on the safety technology.
• the present invention was based on an economical and technically safe and simple process for the preparation of 3-hydroxypyrazoles as an object.
• R 2 , R 3 for hydrogen, cyano, halogen and optionally subst.
• the oxidation of pyrazolidinones II is generally carried out by gassing an aqueous basic solution of II with air or pure oxygen.
• Suitable bases are inorganic or organic, the pK a value of which is greater than 7.
• the process according to the invention does not require complete deprotonation of the compound II.
• the pH of the reaction medium is below 7.
• the process is particularly advantageously carried out at pH> 7.
• the base is added at least equimolar to compound II.
• the base addition increases the solubility of the pyrazolidiones to such an extent that they are accessible for reaction in water.
• inorganic bases such as hydroxides or carbonates of the alkali or alkaline earth metals, such as, for. As sodium hydroxide, potassium hydroxide, magnesium hydroxide, potassium carbonate or sodium carbonate, preferred.
• non-volatile bases are preferred.
• organic bases are also suitable.
• Non-volatile bases are preferred under reaction conditions not only for the reasons mentioned above, but also for safety reasons.
• the process can be carried out in such a way that the oxidation of the reaction mixture is accelerated by adding catalytic amounts of a metal salt.
• the selectivity is increased in most cases.
• Particularly suitable metal salts are salts of iron in the divalent or trivalent oxidation state (for example iron (II) chloride, iron (III) chloride, iron (II) sulfate, iron (III) sulfate, potassium hexacyanoferrate (II) and potassium -hexacyanoferrate-III), salts of copper in the mono- or divalent oxidation state (e.g.
• salts of Cobalt in the bivalent or trivalent oxidation stage eg cobalt-II-acetate, cobalt-II-chloride and cobalt-III-fluoride
• salts of main group or transition metals eg cobalt-II-acetate, cobalt-II-chloride and cobalt-III-fluoride
• salts of main group or transition metals eg cobalt-II-acetate, cobalt-II-chloride and cobalt-III-fluoride
• the metal salts are generally used in amounts of from 0.01 mol% to 20 mol%, preferably 0.3 mol% to 10 mol%, in particular 0.5 mol% to 5 mol%, based on II used.
• a preferred embodiment of the method according to the invention is oxidation with pure oxygen. There is no need for metal salt catalysis.
• This oxidation usually takes place at temperatures from 0 ° C. to the boiling point of the reaction mixture, preferably 20 ° C. to
• the process can be carried out under a pressure of 1 to 200 bar.
• the pressure can be built up by injecting air or pure oxygen or mixtures thereof. Pressures from 1 to 50 bar are advantageous. In particular, pressures from 1 to 20 bar are possible.
• the reaction mixtures are worked up in a customary manner, for example by precipitating the product by neutralizing the reaction solution, optionally extracting, separating the phases and optionally chromatographic purification of the raw products.
• the intermediate and end products are obtained in the form of colorless or slightly brownish, viscous oils, which are freed or purified of volatile components under reduced pressure and at a moderately elevated temperature. If the intermediate and end products are obtained as solids, they can also be purified by recrystallization or digesting.
• alkyl radicals usually contain 1 to 10 carbon atoms
• alkenyl and alkynyl radicals usually consist of 2 to 10 carbon atoms
• cycloalkyl radicals contain 3 to 10 ring members.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Plural Heterocyclic Compounds (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Catalysts (AREA)

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Citations (2)

• 1996
  • 1996-12-17 DE DE19652516A patent/DE19652516A1/de not_active Withdrawn
• 1997
  • 1997-04-12 UA UA99074135A patent/UA53678C2/uk unknown
  • 1997-12-04 SK SK776-99A patent/SK282689B6/sk not_active IP Right Cessation
  • 1997-12-04 AT AT97953736T patent/ATE238994T1/de active
  • 1997-12-04 US US09/319,880 patent/US6040458A/en not_active Expired - Lifetime
  • 1997-12-04 CZ CZ19992147A patent/CZ292280B6/cs not_active IP Right Cessation
  • 1997-12-04 HU HU0000554A patent/HU228235B1/hu not_active IP Right Cessation
  • 1997-12-04 EP EP97953736A patent/EP0946514B1/de not_active Expired - Lifetime
  • 1997-12-04 KR KR10-1999-7005382A patent/KR100508594B1/ko not_active Expired - Fee Related
  • 1997-12-04 ES ES97953736T patent/ES2199382T3/es not_active Expired - Lifetime
  • 1997-12-04 NZ NZ335953A patent/NZ335953A/xx unknown
  • 1997-12-04 CA CA002275253A patent/CA2275253C/en not_active Expired - Fee Related
  • 1997-12-04 CN CN97180756A patent/CN1098253C/zh not_active Expired - Lifetime
  • 1997-12-04 EA EA199900536A patent/EA001630B1/ru not_active IP Right Cessation
  • 1997-12-04 WO PCT/EP1997/006780 patent/WO1998027062A1/de not_active Ceased
  • 1997-12-04 DE DE59709989T patent/DE59709989D1/de not_active Expired - Lifetime
  • 1997-12-04 PL PL333984A patent/PL191331B1/pl unknown
  • 1997-12-04 JP JP52724998A patent/JP4465048B2/ja not_active Expired - Fee Related
  • 1997-12-04 AU AU57536/98A patent/AU746496B2/en not_active Ceased
  • 1997-12-04 DK DK97953736T patent/DK0946514T3/da active
  • 1997-12-04 BR BR9713951A patent/BR9713951A/pt not_active IP Right Cessation
  • 1997-12-04 IL IL13012597A patent/IL130125A/xx not_active IP Right Cessation
  • 1997-12-12 IN IN2867MA1997 patent/IN185466B/en unknown
  • 1997-12-15 ZA ZA9711238A patent/ZA9711238B/xx unknown
  • 1997-12-17 CO CO97073663A patent/CO5011024A1/es unknown
  • 1997-12-17 AR ARP970105956A patent/AR008944A1/es active IP Right Grant

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