CH396927A - Process for the preparation of new pyrazolopyrimidines - Google Patents
Process for the preparation of new pyrazolopyrimidinesInfo
- Publication number
- CH396927A CH396927A CH509965A CH509965A CH396927A CH 396927 A CH396927 A CH 396927A CH 509965 A CH509965 A CH 509965A CH 509965 A CH509965 A CH 509965A CH 396927 A CH396927 A CH 396927A
- Authority
- CH
- Switzerland
- Prior art keywords
- radical
- ethyl
- radicals
- preparation
- alkyl radical
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D487/00—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00
- C07D487/02—Heterocyclic compounds containing nitrogen atoms as the only ring hetero atoms in the condensed system, not provided for by groups C07D451/00 - C07D477/00 in which the condensed system contains two hetero rings
- C07D487/04—Ortho-condensed systems
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
Description
Verfahren zur Herstellung neuer Pyrazolopyrimidine
Gegenstand der Erfindung ist ein Verfahren zur Herstellung ton Pyrazolo[3,4-d]pyrimidinen der Formel
EMI1.1
worin R6 Methyl oder Äthyl bedeutet, R,. für ein Wasserstoffatom oder einen niederen Alkylrest steht und R1 einen Oxaalkyl-, Cycloalkyl- oder Cycloalkylalkylrest oder einen Aralkyl- oder Heterocyclylalkylrest oder einen Alkylrest mit mehr als zwei Kohlenstoffatomen bedeutet, oder ihrer Salze.
In den neuen Verbindungen kommen als Alkylreste insbesondere niedere Alkylreste, wie Methyl-, Äthyl-, Propyl-, Isopropyl-, Butyl-, Isobutyl-, Pentyl (1)-, Pentyl-(2)-, Pentyl-(3)-, 2-Methylbutyl-(3)oder Hexylreste, und als Oxa-alkylreste z. B. 3-Oxa- pentyl-(5)- oder 3-Oxa-heptyl-(6)-reste in Betracht.
Cycloalkyl- oder Cycloalkylalkylreste sind bei- spielsweise Cyclopentyl- oder Cyclohexylreste, oder Cyclopentyl- oder Cyclohexyl-methyl-, -äthyl- oder -propylreste.
Als Aralkylreste kommen insbesondere Phenylalkylreste, wie 1- oder 2-Phenyläthyl- oder Phenylmethylreste in Frage, in denen die aromatischer Kerne Substituenten tragen können, wie niedere Al- kylreste oder freie oder substituierte Hydroxy-, Amino- oder Mercaptogruppen, Halogenatome, Tri finormethyl- oder Nitrogruppen. In den genannten substitutierten Hydroxy-, Mercapto- oder Aminogruppen sind die Substituenten insbesondere solche der oben genannten Art, vor allem niedere Alkyl- reste, so dass es sich z.
B. um Methoxy-, Äthoxy-, Propoxy- oder Butoxygruppen, entsprechende Alkylmercaptogruppen, Alkylendioxygruppen, wie Methylendioxygruppen, Mono- oder Dialkylaminogruppen, wie Mono-oder Dimethyl-, -äthyl-, -propyl-, -butyl-, oder -pentylamirogruppen handelt. Als Halogenatome sind vor allem Fluor-, Chlor- oder Bromatome zu nennen. Die Alkylreste können meh- rere Arylreste enthalten, wie z. B. im Diphenylmethylrest.
Als Heterocyclylalkylreste seien beispielsweise Pyridylmethyl-, Thenyl- oder Furfurylreste, die im heterocyclischen Rest wie oben für die Arylreste angegeben, substituiert sein können, genannt.
Die neuen Verbindungen und ihre Salze besitzen wertvolle pharmakologische Eigenschaften. Insbesondere sind sie coronarerweiternd wirksam. Die neuen Verbindungen können somit als Heilmittel, insbesondere bei Durchblutungsstörungen des Herzmuskels, aber auch als Zwischenprodukte zur Herstellung solcher Heilmittel dienen.
Besonders wertvoll. als coronarerweiternde Mittel sind Verbindungen der Formel
EMI1.2
und ihre tautomeren Formen und Salze davon, wor in. R3 für Wasserstoff oder Niederalkyl steht, RG Me- thyl oder Äthyl darstellt und R, einen Cycloalkyl rest, wie Cyclopentyl oder Cyclohexyl, oder vor allem einen Alkylrest mit mindestens 3 Kohlenstoffatomen, wie Isopropyl, Butyl-(2), Pentyl-(2) oder (3), oder einen Oxaalkylrest, wie 3-Oxa-pentyl-(5) oder 3 -Oxa-heptyl-(6) darstellt.
Zu nennen ist besonders das l-Isopropyl-4hy- droxy-6-äthyl-pyrazolo[3,4-d]pyrimidin und seine Salze.
Das erfindungsgemässe Verfahren zur Herstellung der neuen Verbindungen besteht darin, dass man in einem Nitril der Formel
EMI2.1
die Nitrilgruppe durch Hydrolyse in die Carbamylgruppe überführt, z. B. durch Behandlung mit Alkalien in Gegenwart von Oxydationsmitteln, wie Wasserstoffsuperoxyd, und das erhaltene Produkt cyclisiert. Dabei kann der Ringsohluss gleichzeitig mit der Umwandlung in die Carbamylgruppe erfolgen.
Die erhaltenen 4-Hydroxy-pyrazolopyrimidine können in üblicher Weise in ihre Salze mit Basen, z. B. in ihre Metallsalze, wie Alkalimetallsalze umgewandelt werden, z. B. durch Lösen in Alkalilaugen.
Die Salze ihrerseits lassen sich in die freien Hydroxyverbindungen umwandeln, zweckmässig durch Behandlung mit Säuren.
Die neuen, pharmakologisch wertvollen Verbindungen, ihre Salze oder entsprechende Gemische können z. B. in Form pharmazeutischer Präparate Verwendung finden. Diese enthalten die genannten Verbindungen in Mischung mit einem für die enterale oder parenterale Applikation geeigneten pharmazeutischen organischen oder anorganischen Trägermaterial.
Die verfahrensgemäss erhaltenen Endstoffe sind aber auch wertvolle Zwischenprodukte, z. B. für die Herstellung der im Schweizer Patent Nr. 390264 be schrieb enen 4-Aminoverbindungen.
Sofern die beim erfindungsgemässen Verfahren verwendeten Ausgangsstoffe neu sind, lassen sie sich nach an sich bekannten Methoden herstellen.
Als Ausgangsstoffe werden gemäss der vorliegenden Erfindung vorzugsweise diejenigen verwendet, die zu den eingangs als besonders wertvoll ge schilderten Endstoffen führen.
Im nachfolgen, den Beispiel sind die Temperaturen in Celsiusgraden angegeben.
Beispiel
30 g 2-Isopropyl-3 mino-4-pyrazol-carbonsäure- nitril werden mit 68 ml Acetanhydrid während 10 Stunden am Rückiluss gekocht. Der aus der einge dampften Reaktionslösung erhaltene Rückstand wird einmal aus Äther und anschliessend aus Wasser umgelöst. Die Mutterlauge wird eingedampft und man erhält eine zähflüssige Masse, die das 2-Isopropyl-3 (acetylamino)-4-pyrazol-carbonsäurenitril enthält.
3,84 g dieser Masse werden in 14 ml 1O0/o iger wässriger Kalilauge und 30 ml 3%igem Wasserstoffsuperoxyd während 30 Minuten auf dem Wasserbad erwärmt. Man filtriert von wenig Unlöslichem ab, säuert das Filtrat mit 2-n. Salzsäure an, worauf sich das 1-Isopropyl-4-hydroxy-6-methyl-pyrazolo[3,4-d]pyrimidin der Formel
EMI2.2
ausscheidet. Nach einmaligem Umkristallisieren aus Alkohol beträgt der F. 195-1960.
In analoger Weise kann man das 1-Isopropyl-4 hydroxy-6-äthylyrazolo [3,4-d]pyrimidin, F. 180 bis 1820 (aus Äthanol) herstellen.
Process for the preparation of new pyrazolopyrimidines
The invention relates to a process for the preparation of pyrazolo [3,4-d] pyrimidines of the formula
EMI1.1
wherein R6 is methyl or ethyl, R ,. represents a hydrogen atom or a lower alkyl radical and R1 represents an oxaalkyl, cycloalkyl or cycloalkylalkyl radical or an aralkyl or heterocyclylalkyl radical or an alkyl radical having more than two carbon atoms, or their salts.
In the new compounds, lower alkyl radicals such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl (1), pentyl (2), pentyl (3), 2-methylbutyl (3) or hexyl radicals, and as oxa-alkyl radicals, for. B. 3-oxapentyl (5) - or 3-oxa-heptyl (6) radicals into consideration.
Cycloalkyl or cycloalkylalkyl radicals are, for example, cyclopentyl or cyclohexyl radicals, or cyclopentyl or cyclohexyl-methyl, -ethyl or -propyl radicals.
Particularly suitable aralkyl radicals are phenylalkyl radicals, such as 1- or 2-phenylethyl or phenylmethyl radicals, in which the aromatic nuclei can carry substituents, such as lower alkyl radicals or free or substituted hydroxy, amino or mercapto groups, halogen atoms, tri finormethyl or nitro groups. In the substituted hydroxyl, mercapto or amino groups mentioned, the substituents are in particular those of the type mentioned above, especially lower alkyl radicals, so that there are, for.
B. methoxy, ethoxy, propoxy or butoxy groups, corresponding alkyl mercapto groups, alkylenedioxy groups, such as methylenedioxy groups, mono- or dialkylamino groups, such as mono- or dimethyl, -ethyl, -propyl, -butyl, or -pentylamiro groups . Particularly fluorine, chlorine or bromine atoms should be mentioned as halogen atoms. The alkyl radicals can contain several aryl radicals, such as. B. in the diphenylmethyl radical.
Examples of heterocyclylalkyl radicals which may be mentioned are pyridylmethyl, thenyl or furfuryl radicals, which can be substituted in the heterocyclic radical as indicated above for the aryl radicals.
The new compounds and their salts have valuable pharmacological properties. In particular, they are effective in expanding the coronary artery. The new compounds can thus serve as remedies, in particular in the case of circulatory disorders of the heart muscle, but also as intermediate products for the production of such remedies.
Particularly valuable. as coronary-expanding agents are compounds of the formula
EMI1.2
and their tautomeric forms and salts thereof, in which R3 is hydrogen or lower alkyl, RG is methyl or ethyl and R is a cycloalkyl radical, such as cyclopentyl or cyclohexyl, or above all an alkyl radical with at least 3 carbon atoms, such as isopropyl, Butyl- (2), pentyl- (2) or (3), or an oxaalkyl radical, such as 3-oxa-pentyl- (5) or 3-oxa-heptyl- (6).
Particular mention should be made of 1-isopropyl-4-hydroxy-6-ethyl-pyrazolo [3,4-d] pyrimidine and its salts.
The inventive method for the preparation of the new compounds consists in that one in a nitrile of the formula
EMI2.1
the nitrile group converted into the carbamyl group by hydrolysis, e.g. B. by treatment with alkalis in the presence of oxidizing agents such as hydrogen peroxide, and the product obtained is cyclized. The ring base can take place simultaneously with the conversion into the carbamyl group.
The 4-hydroxy-pyrazolopyrimidines obtained can be converted into their salts with bases, eg. B. converted into their metal salts such as alkali metal salts, e.g. B. by dissolving in alkaline solutions.
The salts, for their part, can be converted into the free hydroxy compounds, conveniently by treatment with acids.
The new, pharmacologically valuable compounds, their salts or mixtures thereof can, for. B. find use in the form of pharmaceutical preparations. These contain the compounds mentioned in a mixture with a pharmaceutical, organic or inorganic carrier material suitable for enteral or parenteral administration.
The end products obtained according to the process are also valuable intermediates, eg. B. for the preparation of the enen 4-amino compounds in Swiss Patent No. 390264 be wrote.
If the starting materials used in the process according to the invention are new, they can be produced by methods known per se.
According to the present invention, the starting materials used are preferably those which lead to the end materials described at the beginning as being particularly valuable.
In the following example, the temperatures are given in degrees Celsius.
example
30 g of 2-isopropyl-3-mino-4-pyrazole-carboxylic acid nitrile are boiled with 68 ml of acetic anhydride for 10 hours under reflux. The residue obtained from the evaporated reaction solution is redissolved once from ether and then from water. The mother liquor is evaporated and a viscous mass is obtained which contains 2-isopropyl-3 (acetylamino) -4-pyrazole-carboxylic acid nitrile.
3.84 g of this mass are heated in 14 ml of 10% strength aqueous potassium hydroxide solution and 30 ml of 3% strength hydrogen peroxide for 30 minutes on a water bath. Little insolubles are filtered off, and the filtrate is acidified with 2-n. Hydrochloric acid, whereupon the 1-isopropyl-4-hydroxy-6-methyl-pyrazolo [3,4-d] pyrimidine of the formula
EMI2.2
is eliminated. After recrystallizing once from alcohol, the F. is 195-1960.
1-Isopropyl-4-hydroxy-6-äthylyrazolo [3,4-d] pyrimidine, mp 180 to 1820 (from ethanol) can be prepared in a similar manner.
Claims (1)
Priority Applications (1)
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CH509965A CH396927A (en) | 1960-05-11 | 1960-05-11 | Process for the preparation of new pyrazolopyrimidines |
Applications Claiming Priority (1)
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CH509965A CH396927A (en) | 1960-05-11 | 1960-05-11 | Process for the preparation of new pyrazolopyrimidines |
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CH396927A true CH396927A (en) | 1965-08-15 |
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CH509965A CH396927A (en) | 1960-05-11 | 1960-05-11 | Process for the preparation of new pyrazolopyrimidines |
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Cited By (15)
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US7488733B2 (en) | 2003-06-25 | 2009-02-10 | Boehringer Ingelheim International Gmbh | 6-arylamino-5-cyano-4-pyrimidinones as pde9a inhibitors |
US7615558B2 (en) | 2003-05-09 | 2009-11-10 | Boehringer Ingelheim International Gmbh | 6-arylmethylprazolo[3,4-d]pyrimidines |
US7737156B2 (en) | 2002-08-23 | 2010-06-15 | Boehringer Ingelheim International Gmbh | Selective phosphodiesterase 9A inhibitors as medicaments for improving cognitive processes |
WO2010112437A1 (en) | 2009-03-31 | 2010-10-07 | Boehringer Ingelheim International Gmbh | 1-heterocyclyl-1, 5-dihydro-pyrazolo [3, 4-d] pyrimidin-4-one derivatives and their use as pde9a modulators |
EP2298773A1 (en) | 2003-05-09 | 2011-03-23 | Boehringer Ingelheim International GmbH | 6-Cyclomethyl and 6-alkylmethyl substituted pyrazolopyrimidines |
US8039477B2 (en) * | 2002-08-23 | 2011-10-18 | Boehringer Ingelheim International Gmbh | Substituted pyrazolo[3,4-d]pyrimidin-4-one compounds as phosphodiesterase inhibitors |
US8044060B2 (en) | 2003-05-09 | 2011-10-25 | Boehringer Ingelheim International Gmbh | 6-cyclylmethyl- and 6-alkylmethyl pyrazolo[3,4-D]pyrimidines, methods for their preparation and methods for their use to treat impairments of perception, concentration learning and/or memory |
US8088769B2 (en) | 2004-01-14 | 2012-01-03 | Boehringer Ingelheim International Gmbh | Cyanopyrimidinones |
WO2012020022A1 (en) | 2010-08-12 | 2012-02-16 | Boehringer Ingelheim International Gmbh | 6-cycloalkyl-1, 5-dihydro-pyrazolo [3, 4-d] pyrimidin-4-one derivatives and their use as pde9a inhibitors |
US8158633B2 (en) | 2002-08-23 | 2012-04-17 | Boehringer Ingelheim International Gmbh | Phenyl-substituted pyrazolopyrimidines |
WO2012110441A1 (en) | 2011-02-15 | 2012-08-23 | Boehringer Ingelheim International Gmbh | 6-cycloalkyl-pyrazolopyrimidinones for the treatment of cns disorders |
WO2012110440A1 (en) | 2011-02-14 | 2012-08-23 | Boehringer Ingelheim International Gmbh | 6 - cyclobutyl - 1, 5 - dihydro - pyrazolo [3, 4-d] pyrimidin- 4 - one derivatives their use as pde9a inhibitors |
US8623879B2 (en) | 2008-04-02 | 2014-01-07 | Boehringer Ingelheim International Gmbh | 1-heterocyclyl-1,5-dihydro-pyrazolo[3,4-D] pyrimidin-4-one derivates and their use as PDE9A modulators |
US8648085B2 (en) | 2007-11-30 | 2014-02-11 | Boehringer Ingelheim International Gmbh | 1, 5-dihydro-pyrazolo (3, 4-D) pyrimidin-4-one derivatives and their use as PDE9A mudulators for the treatment of CNS disorders |
US9079905B2 (en) | 2008-09-08 | 2015-07-14 | Boehringer Ingelheim International Gmbh | Compounds for the treatment of CNS disorders |
-
1960
- 1960-05-11 CH CH509965A patent/CH396927A/en unknown
Cited By (30)
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US8158633B2 (en) | 2002-08-23 | 2012-04-17 | Boehringer Ingelheim International Gmbh | Phenyl-substituted pyrazolopyrimidines |
US9067945B2 (en) | 2002-08-23 | 2015-06-30 | Boehringer Ingehleim International GmbH | Selective phosphodiesterase 9A inhibitors as medicaments for improving cognitive processes |
US7737156B2 (en) | 2002-08-23 | 2010-06-15 | Boehringer Ingelheim International Gmbh | Selective phosphodiesterase 9A inhibitors as medicaments for improving cognitive processes |
US8741907B2 (en) | 2002-08-23 | 2014-06-03 | Boehringer Ingelheim International Gmbh | Alkyl-substituted pyrazolopyrimidines |
US8455502B2 (en) | 2002-08-23 | 2013-06-04 | Boehringer Ingelheim International Gmbh | Selective phosphodiesterase 9A inhibitors as medicaments for improving cognitive processes |
EP2305262A1 (en) | 2002-08-23 | 2011-04-06 | Boehringer Ingelheim International GmbH | Selective PDE9A inhibitors as medicaments for the improvement of cognitive processes |
US8039477B2 (en) * | 2002-08-23 | 2011-10-18 | Boehringer Ingelheim International Gmbh | Substituted pyrazolo[3,4-d]pyrimidin-4-one compounds as phosphodiesterase inhibitors |
US8044060B2 (en) | 2003-05-09 | 2011-10-25 | Boehringer Ingelheim International Gmbh | 6-cyclylmethyl- and 6-alkylmethyl pyrazolo[3,4-D]pyrimidines, methods for their preparation and methods for their use to treat impairments of perception, concentration learning and/or memory |
US8642605B2 (en) | 2003-05-09 | 2014-02-04 | Boehringer Ingelheim International Gmbh | 6-cyclylmethyl-and 6-alkylmethyl-substituted pyrazolepyrimidines |
US7615558B2 (en) | 2003-05-09 | 2009-11-10 | Boehringer Ingelheim International Gmbh | 6-arylmethylprazolo[3,4-d]pyrimidines |
US8822479B2 (en) | 2003-05-09 | 2014-09-02 | Boehringer Ingelheim International Gmbh | 6-cyclylmethyl-and 6-alkylmethyl-substituted pyrazolepyrimidines |
US8809348B2 (en) | 2003-05-09 | 2014-08-19 | Boehringer Ingelheim International Gmbh | 6-arylmethyl substituted pyrazolo[3,4-d]pyrimidines |
EP2298773A1 (en) | 2003-05-09 | 2011-03-23 | Boehringer Ingelheim International GmbH | 6-Cyclomethyl and 6-alkylmethyl substituted pyrazolopyrimidines |
US7488733B2 (en) | 2003-06-25 | 2009-02-10 | Boehringer Ingelheim International Gmbh | 6-arylamino-5-cyano-4-pyrimidinones as pde9a inhibitors |
US8431573B2 (en) | 2004-01-14 | 2013-04-30 | Boehringer Ingelheim International Gmbh | Cyanopyrimidinones |
US8088769B2 (en) | 2004-01-14 | 2012-01-03 | Boehringer Ingelheim International Gmbh | Cyanopyrimidinones |
US8648085B2 (en) | 2007-11-30 | 2014-02-11 | Boehringer Ingelheim International Gmbh | 1, 5-dihydro-pyrazolo (3, 4-D) pyrimidin-4-one derivatives and their use as PDE9A mudulators for the treatment of CNS disorders |
US8623879B2 (en) | 2008-04-02 | 2014-01-07 | Boehringer Ingelheim International Gmbh | 1-heterocyclyl-1,5-dihydro-pyrazolo[3,4-D] pyrimidin-4-one derivates and their use as PDE9A modulators |
US9096603B2 (en) | 2008-04-02 | 2015-08-04 | Boehringer Ingelheim International Gmbh | 1-heterocyclyl-1,5-dihydro-pyrazolo[3,4-D] pyrimidin-4-one derivatives and their use as PDE9A modulators |
US9079905B2 (en) | 2008-09-08 | 2015-07-14 | Boehringer Ingelheim International Gmbh | Compounds for the treatment of CNS disorders |
US8623901B2 (en) | 2009-03-31 | 2014-01-07 | Boehringer Ingelheim International Gmbh | Compounds for the treatment of CNS disorders |
WO2010112437A1 (en) | 2009-03-31 | 2010-10-07 | Boehringer Ingelheim International Gmbh | 1-heterocyclyl-1, 5-dihydro-pyrazolo [3, 4-d] pyrimidin-4-one derivatives and their use as pde9a modulators |
US9102679B2 (en) | 2009-03-31 | 2015-08-11 | Boehringer Ingelheim International Gmbh | Compounds for the treatment of CNS disorders |
US8912201B2 (en) | 2010-08-12 | 2014-12-16 | Boehringer Ingelheim International Gmbh | 6-cycloalkyl-pyrazolopyrimidinones for the treatment of CNS disorders |
WO2012020022A1 (en) | 2010-08-12 | 2012-02-16 | Boehringer Ingelheim International Gmbh | 6-cycloalkyl-1, 5-dihydro-pyrazolo [3, 4-d] pyrimidin-4-one derivatives and their use as pde9a inhibitors |
US9328120B2 (en) | 2010-08-12 | 2016-05-03 | Boehringer Ingelheim International Gmbh | 6-cycloalkyl-pyrazolopyrimidinones for the treatment of CNS disorders |
EP3053924A1 (en) | 2010-08-12 | 2016-08-10 | Boehringer Ingelheim International Gmbh | 6-cycloalkyl-1, 5-dihydro-pyrazolo [3, 4-d]pyrimidin-4-one derivatives and their use as pde9a inhibitors |
WO2012110440A1 (en) | 2011-02-14 | 2012-08-23 | Boehringer Ingelheim International Gmbh | 6 - cyclobutyl - 1, 5 - dihydro - pyrazolo [3, 4-d] pyrimidin- 4 - one derivatives their use as pde9a inhibitors |
WO2012110441A1 (en) | 2011-02-15 | 2012-08-23 | Boehringer Ingelheim International Gmbh | 6-cycloalkyl-pyrazolopyrimidinones for the treatment of cns disorders |
US8809345B2 (en) | 2011-02-15 | 2014-08-19 | Boehringer Ingelheim International Gmbh | 6-cycloalkyl-pyrazolopyrimidinones for the treatment of CNS disorders |
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