CS261658B1 - Flux for welding-on by high-alloyed belt electrode - Google Patents
Flux for welding-on by high-alloyed belt electrode Download PDFInfo
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Abstract
Riešenie sa týká sposobu přípravy 5-alkyltioi-2-substituovaných-3-oxo-2H-pyridazín- -4-olov všeobecného vzorca I, v ktorom R* 1 znamená alkyl s 1 až 6 atómami uhlíka, fenyl, cyklobexyl, benzyl, tolyl, chlórfenyl, 3-trifluórmetyl-4-chlórfenyl, R-! znamená alkyl s 1 až 3 atómami uhlíka, záhrevom příslušného 4-alkoxy-2-substituovaného- -3-oxo-2H-pyridazín-5-tiolu alebo jeho soli s alkalickým kovám pri teplote 60 až 140 °C v prostředí protónakceptorného rozpúšťadla zo skupiny zahřňujúcej metanol, etanol, propanol, dimetylsulfoxid, dimetylformamid, trietylamín, nitril kyseliny octovej a v případe použitia soli s alkalickým kovom i v prostředí vody, pričom pri reakcii nastane elektrofllný prešmyk katlónu R2. Riešenie je možné využit v chemickom priemysle.The present invention relates to a process for the preparation of 5-alkylthio-2-substituted-3-oxo-2H-pyridazine. Of 4-ols of formula I in which R 1 is alkyl of 1 to 6 carbon atoms; phenyl, cyclobexyl, benzyl, tolyl, chlorophenyl, 3-trifluoromethyl-4-chlorophenyl; means alkyl having 1 to 3 carbon atoms, heating the corresponding 4-alkoxy-2-substituted- 3-oxo-2H-pyridazine-5-thiol or its salts with alkaline metal at 60 to 140 ° C in a proton-acceptor solvent environment from the methanol, ethanol, propanol, dimethylsulfoxide, dimethylformamide, triethylamine, acetic acid nitrile; the use of alkali metal salt in water, with the reaction occurring electrophilic catlon R2 rearrangement. The solution is possible in the chemical industry.
Description
Vynález sa týka spôsobu prípravy 5-alkyl-tio-2-substituovaných-3-oxo-2H-pyridazín-4--olov všeobecného vzorca I
v ktorom R1 znamená alkyl s 1 až 6 atómami uhlíka, fenyl, cyklohexyl, benzyl, tolyl, chlórfe-nyl, 3-trifluórmetyl-4-chlórfenyl a R2 znamená alkyl s 1 až 3 atómami uhlíka. Tieto zlúčeniny sú použiteľné ako medziprodukty k syntéze biologicky účinných látok.
Z literatúry je známy spôsob prípravy 5--alkyltio-2-substituovaných-3-oxo-2H-pyri-dazín-4-olov všeobecného vzorca I reakciou 5-alkylt»-4-halogén-2-substituovaného-3--oxo-2H-pyridazínu všeobecného vzorca III
v ktorom R1 a R2 majú už uvedený význam, X znamená halogén s hydroxidom sodným alebo draselným. [CS 175 205; Chem. zvesti 30; 663—673 (1976)].
Teraz sa zistil nový spôsob prípravy 5--alkyltio-2-substituovaných-3-oxo-2H-pyrida-zín-4-olov všeobecného vzorca I v ktorom
R1 a R2· majú už uvedený význam, reakciou 4-alkoxy-2-substituovaného-3-oxo-2H-pyrida-zín-5-tiolu alebo jeho soli s alkalickým kovom všeobecného vzorca II y ktorom
R1 a R2 majú už uvedený význam, M znamená vodík, sodík alebo draslík v prostredí protonoakceptorného organického rozpúšťadla zo skupiny zahrňujúcej metanol, etanol, propanol, dimetylsulfoxid, dimetylform-amid, trietylamín, nitril kyseliny octovej a ak M znamená sodík alebo draslík i v prostredí vody, pri teplote 60 až 140 °C, pričom pri reakcii nastane elektrofilný prešmyk katiónu R2.
Nasledujúce príklady ilustrujú, ale neobmedzujú predmet vynálezu.
Príklad 1
Príprava 2-metyl-5-metyltio -3-oxo-2H-py-ridazín-4-olu 1,5 g 4-metoxy-2-metyl-3~oxo-2II-pyľitla-zín-5-tiolu sa miešalo v 20 ml dimetylsulfo-xidu pri teplote 80 °C 4 hodiny. Dimetylsulfoxid sa oddestiloval za zníženého tlaku, zvyšok sa potom prekryštalizoval z toluénu (30 ml). Získalo sa 0,8 g bielej kryštalickej látky s teplotou topenia 156—158 °C. Analýza pre Ο6Η8Ν2Ο28 (m. h. = 172,2) vypočítané: 16,22 % N, 18,62 % S, 7ÍctpnfS· 16,01 % N, 19,11 % S. IČ v CHC1S: p (C=O) = 1615 cm“1, v (O—H) = 3 370 cm-1.
Príklad 2
Príprava 2-fenyl-5-metyltio-3-oxo-2H-pyrida-zín-4-olu 1,5 g 2-fenyl-4-metoxy-3-oxo-2H-pyridazín--5-tiolu sa miešalo v 20 ml trietylamínu 4 hodiny pri teplote 80 °C. Trietylamín sa oddestiloval za zníženého tlaku, zvyšok sa potom prekryštalizoval z etanolu (20 ml). Získalo sa 0,7 g bielej kryštalickej látky s t. t. 214—216 °C.
Analýza pre CnH10N2O2S (m. h. 234,26) vypočítané: 11,95 % N, .13,69 % S, zistené: 12,16 % N, 13,88 % S. IC v CHCLp v (G=O) 1 630 cm-1, p (OH) = 3 360 cm-1.
Príklad 3
Príprava 2-(3-chlórfenyl)-5-metyltio-3-oxo--2H-pyridazín-4-olu
The present invention relates to a process for the preparation of 5-alkylthio-2-substituted-3-oxo-2H-pyridazin-4-ol of formula I
wherein R 1 is alkyl of 1 to 6 carbon atoms, phenyl, cyclohexyl, benzyl, tolyl, chlorophenyl, 3-trifluoromethyl-4-chlorophenyl and R 2 is alkyl of 1 to 3 carbon atoms. These compounds are useful as intermediates in the synthesis of biologically active substances.
From the literature, a process for the preparation of 5-alkylthio-2-substituted-3-oxo-2H-pyridazin-4-ol of general formula I by reaction of 5-alkylthio-4-halo-2-substituted-3-oxo- 2H-pyridazine of formula III
wherein R 1 and R 2 are as defined above, X is halogen with sodium or potassium hydroxide. [CS 175 205; Chem. rumors 30; 663-673 (1976)].
A novel process has now been found for the preparation of 5-alkylthio-2-substituted-3-oxo-2H-pyridazin-4-ols of general formula I in which
R1 and R2 are as defined above by reacting a 4-alkoxy-2-substituted-3-oxo-2H-pyridazin-5-thiol or an alkali metal salt thereof of the formula (II) wherein
R 1 and R 2 are as defined above, M is hydrogen, sodium or potassium in an environment of a protonacceptor organic solvent such as methanol, ethanol, propanol, dimethylsulfoxide, dimethylformamide, triethylamine, acetic acid nitrile and when M is sodium or potassium in the environment water, at a temperature of 60 to 140 ° C, with electrophilic rearrangement of the cation R2 occurring in the reaction.
The following examples illustrate, but do not limit the invention.
Example 1
Preparation of 2-methyl-5-methylthio-3-oxo-2H-pyridazin-4-ol 1.5 g of 4-methoxy-2-methyl-3-oxo-2II-pyrithilane-5-thiol was stirred in 20 ml of dimethylsulfoxide at 80 ° C for 4 hours. The dimethyl sulfoxide was distilled off under reduced pressure, and then the residue was recrystallized from toluene (30 ml). 0.8 g of a white crystalline solid with a melting point of 156-158 ° C was obtained. Analysis for Ο6Η8Ν2Ο28 (mh = 172.2) calculated: 16.22% N, 18.62% S, 7ctctpnfS · 16.01% N, 19.11% S. IR in CHClS: p (C = O) = 1615 cm -1, v (O-H) = 3,370 cm -1.
Example 2
Preparation of 2-phenyl-5-methylthio-3-oxo-2H-pyridazin-4-ol 1.5 g of 2-phenyl-4-methoxy-3-oxo-2H-pyridazine-5-thiol were stirred at 20 ° C. ml of triethylamine at 80 ° C for 4 hours. Triethylamine was distilled off under reduced pressure, and then the residue was recrystallized from ethanol (20 ml). 0.7 g of a white crystalline solid was obtained, mp 214-216 ° C.
Analysis for C 11 H 10 N 2 O 2 S (m / z 234.26) calculated: 11.95% N, 13.69% S, found: 12.16% N, 13.88% S IC in CHCl 2 v (G = O) 1 630 cm -1, p (OH) = 3,360 cm -1.
Example 3
Preparation of 2- (3-chlorophenyl) -5-methylthio-3-oxo-2H-pyridazin-4-ol
Claims (1)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CS874373A CS261658B1 (en) | 1987-06-15 | 1987-06-15 | Flux for welding-on by high-alloyed belt electrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CS874373A CS261658B1 (en) | 1987-06-15 | 1987-06-15 | Flux for welding-on by high-alloyed belt electrode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CS437387A1 CS437387A1 (en) | 1988-07-15 |
| CS261658B1 true CS261658B1 (en) | 1989-02-10 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CS874373A CS261658B1 (en) | 1987-06-15 | 1987-06-15 | Flux for welding-on by high-alloyed belt electrode |
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| CS (1) | CS261658B1 (en) |
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1987
- 1987-06-15 CS CS874373A patent/CS261658B1/en unknown
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| Publication number | Publication date |
|---|---|
| CS437387A1 (en) | 1988-07-15 |
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