- Preparation method of benzotriazole ultraviolet light absorber
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The invention relates to a preparation method of a benzotriazole ultraviolet absorbent. The method comprises the following steps: under the action of a magnesium oxide supported metal catalyst, carrying out transfer hydrogenation reaction on an azo intermediate shown in a formula I and a hydrogen donor to obtain a target product shown in a formula III. The method provided by the invention is small in catalyst dosage, the raw material conversion rate can reach 100%, and the target product selectivity is 90% or above.
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Paragraph 0174; 0177-0178; 0193
(2021/04/14)
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- Method to prepare benzotriazole ultraviolet-absorbing agent via catalytic hydrogen process
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The invention relates to a method to prepare a benzotriazole ultraviolet-absorbing agent via a catalytic hydrogen transfer process. The method includes: before hydrogen transfer reaction, refining thereaction material an azobenzene compound, fully removing impurities that disturb the hydrogen transfer reaction to obtain purity of 99% and above, and performing hydrogen transfer reaction. The refining of the material ensures smoothness for the subsequent hydrogen transfer reaction, and the benzotriazole ultraviolet-absorbing agent of high yield and high purity can be obtained; in addition, themethod has significantly reduced usage of quinone catalysts, is green and low in cost and is suitable for industrial production routes.
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Paragraph 0072; 0075; 0076
(2018/07/15)
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- Preparation method of ultraviolet absorbent containing chlorobenzotriazole
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The invention relates to a preparation method of an ultraviolet absorbent containing chlorobenzotriazole. Azobenzene, sodium hydroxide and toluene are stirred and mixed, the temperature is controlled to 60-80 DEG C, water and hydrazine are dropwise added at a constant speed, heat preservation reaction is performed after the completion of dropping, hydrochloric acid is added to perform neutralization to reach the pH of 6-7 after completion of hydrazine reduction, washing is performed, and an oil phase, namely nitrogen oxide, is obtained; the nitrogen oxide solution, alkali, a framework nickel catalyst and a catalyst promoter sodium phosphite are put into an autoclave, and hydrogen is led to perform constant-pressure constant-temperature reaction after nitrogen displacement; after reaction is completed, reaction liquid filtration and washing are performed, an organic phase evaporated solvent is obtained, and recrystallization, filtration and drying are conducted on the methanol and toluene mixed solvent to obtain the ultraviolet absorbent containing chlorobenzotriazole. Compared with an existing synthetic method, the preparation method has the advantages of being good in reaction selectivity, inhibiting a dechlorination phenomenon in the hydrogenation process, producing few by-products and the like and meanwhile does not produce wastewater containing zinc and aluminum, subsequent processing is simple, and the 'three wastes' problem produced in the secondary reduction process is solved.
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Paragraph 0044-0071
(2017/07/20)
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- Preparation method of benzotriazole light stabilizer
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The invention discloses a preparation method of a benzotriazole ultraviolet light stabilizer. The method comprises the following steps: adding an azo dye intermediate represented by formula I to hydrazine hydrate, carrying out reduction to form an intermediate nitrogen oxide represented by formula II, and reducing the intermediate nitrogen oxide represented by formula II with hydrogen to prepare the benzotriazole ultraviolet light stabilizer represented by formula III, wherein the formula I, the formula II and the formula III are respectively shown in the description, and R in the formulas is C(CH3)3 or CH3. The preparation method allows wastewater generated in the invention to be environmentally-friendly.
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- Preparation of 2-aryl-2H-benzotriazoles by zinc-mediated reductive cyclization of o-nitrophenylazophenols in aqueous media without the use of organic solvents
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Zinc powder-mediated reductive cyclization of o-nitrophenylazophenols in alkaline solution affords the corresponding 2-aryl-2H-benzotriazoles in high yields under mild reaction conditions. No organic solvents are used in the reaction and only minimal amounts in the work-up.
- Liu, Guo-Bin,Zhao, Hong-Yun,Yang, Hong-Jie,Gao, Xiang,Li, Miao-Kui,Thiemann, Thies
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p. 1637 - 1640
(2008/02/11)
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- METHOD FOR PREPARING 2-(2-HYRDROXYPHENYL)-2H-BENZOTRIAZOLE
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This invention provides a method for preparing 2-(2-hydroxyphenyl)-2H-benzotriazole of formula (I) below, consisting of steps of a) performing a first reduction in which hydrazine hydrate is added to a compound of formula (II) below with or without a phase transition catalyst in the presence of solvents which include a nonpolar solvent, water, and an alkaline compound, thereby preparing a compound of formula (III) below, and b) performing a second reduction in which water is added to the compound of formula (III) prepared in step a), and then zinc powder and sulfuric acid are added thereto with or without the phase transition catalyst, wherein, X is halogen or hydrogen, R is hydrogen, C1-C12 alkyl, C5-C8 cycloalkyl, phenyl, or phenyl-C1-C4 alkyl; and R' is C1-C12 alkyl, C5-C8 cycloalkyl, phenyl, or phenyl-C1-C4 alkyl
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- 4-Formyl amino-n-methylpiperidine derivatives, the use thereof as stabilisers and organic material stabilised therewith
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The present invention relates to 4-formylamino-N-methylpiperidine derivatives of the formula (I) where the variables are as defined in the Description, to a process for preparing these piperidine derivatives, to the use of these piperidine derivatives of the invention, or prepared according to the invention, for stabilizing organic material, in particular for stabilizing plastics or coating materials, and also to the use of these piperidine derivatives of the invention, or prepared according to the invention, as light stabilizers or stabilizers for wood surfaces. The present invention further relates to stabilized organic material which comprises these piperidine derivatives of the invention or prepared according to the invention.
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- 2-(2′-hydroxyphenyl)benzotriazoles used as U.V. stabilizers
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2-(2′-hydroxyphenyl)benzotriazoles having general formula (I). The above 2-(2′-hydroxyphenyl)benzotriazoles are useful as light stabilizers for organic polymers.
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- 2-(2′-hydroxyphenyl) benzotriazoles containing a 2,4-imidazolidinedione group and process for their preparation
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2-(2′-hydroxyphenyl)benzotriazoles having general formula (I). The above 2-(2′-hydroyzphenyl)benzotriazoles having general formula (I) are useful as heat, oxygen and light stabilizers for organic polymers. In particular they are useful as UV stabilizers for organic polymers.
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- Liposomogenic UV absorbers
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PCT No. PCT/EP96/00959 Sec. 371 Date Sep. 15, 1997 Sec. 102(e) Date Sep. 15, 1997 PCT Filed Mar. 7, 1996 PCT Pub. No. WO96/29302 PCT Pub. Date Sep. 26, 1996There are described liposomogenic UV absorbers, comprising a hydrophilic head group (=Z), a spacer (=W), a UV chromophore (Q) having an absorption in the range from 285 to 400 nm and at least one hydrophobic tail group (=A) of the formula (1), in which A1 and A2, independently of one another, are a hydrophobic radical, Q is a UV chromophore, W is an organic radical, Z1 and Z2, independently of one another, are a hydrophilic radical, n1 and n2, independently of one another, are a number from 0 to 4, n1=n2=0 not being additionally included, p is 1 or 2, q is a number from 0 to 3, r1 is 1 or 2, r2 is 0 or 1, and s1 is a number from 1 to 3. The liposomogenic UV absorbers according to the invention are preferably used as sunscreen agents in cosmetic preparations. They are capable of self-organization into bimolecular layers, and can thereby penetrate into the stratum corneum to a high extent and behave there in an extremely wash-resistant manner.
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- Phosphites and their production and use
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Phosphites represented by the general formula (I): STR1 wherein R1, R2, R4 and R5 independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkylcycloalkyl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms or a phenyl group; R3 and R6 independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; X1 is a dihydric alcohol residue, wherein HO--X1 --OH defines the corresponding dihydric alcohol from which residue X1, is obtained; and X2 is a direct bond or an alkylene group having 1 to 8 carbon atoms; and the phosphites are useful as stabilizers for organic materials.
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- Piperidine compound, a process for producing the same and a stabilizer using the same
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2-Methyl-3-(2,2,6,6-tetramethyl-4-piperidylamino)-N-(2,2,6,6-tetramethyl-4-piperidyl)-propionamide represented by the following formula, a process for producing the same and a stabilized organic material composition containing the same wherein the piperidine compound imparts excellent properties, such as light stability or thermal stability to the organic materials. STR1
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- Method of preparing 2-phenyl benzotriazoles
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A method of preparing 2-phenylbenzotriazoles expressed by Formula I: STR1 (wherein R1 denotes a hydrogen or chlorine atom, a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxyl group having 1 to 4 carbon atoms, a carboxyl group or a sulfonic acid group; R2 denotes a hydrogen or chlorine atom, a lower alkyl group having 1 to 4 carbon atoms or a lower alkoxyl group having 1 to 4 carbon atoms; R3 denotes a hydrogen or chlorine atom, an alkyl group having 1 to 12 carbon atoms, a lower alkoxyl group having 1 to 4 carbon atoms, a phenyl group, a phenyl group substituted by an alkyl group having 1 to 8 carbon atoms, a phenoxy group or a phenylalkyl group with an alkyl part having 1 to 4 carbon atoms; R4 denotes a hydrogen or chlorine atom, a hydroxyl group or an alkoxyl group having 1 to 4 carbon atoms; and R5 denotes a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a phenylalkyl group with an alkyl part having 1 to 4 carbon atoms) comprises reduction with hydrogen of o-nitroazobenzene derivatives expressed by Formula II: STR2 (wherein R1, R2, R3, R4 and R5 each denote the same as in Formula I), the reduction being effected in a solvent containing water.
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- Method of preparing 2-phenyl benezothriazoles
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A method of preparing 2-phenylbenzotriazoles expressed by Formula I: STR1 (wherein R1 denotes a hydrogen or chlorine atom, a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxyl group having 1 to 4 carbon atoms, a carboxyl group or a sulfonic acid group; R2 denotes a hydrogen or chlorine atom, a lower alkyl group having 1 to 4 carbon atoms or a lower alkoxyl group having 1 to 4 carbon atoms; R3 denotes a hydrogen or chlorine atom, an alkyl group having 1 to 12 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms, a phenyl group, a phenyl group substituted by an alkyl group having 1 to 8 carbon atoms, a phenoxy group or a phenylalkyl group with an alkyl part having 1 to 4 carbon atoms; R4 denotes a hydrogen or chlorine atom, a hydroxyl group or an alkoxyl group having 1 to 4 carbon atoms; and R5 denotes a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or a phenylalkyl group with an alkyl part having 1 to 4 carbon atoms) comprises reducing with hydrogen 2-phenylbenzotriazole-N-oxides expressed by Formula II: STR2 (wherein R1, R2, R3, R4 and R5 each denotes the same as in Formula I).
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- Process for the preparation of benzotriazole derivatives
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Hologenated 2-(2-hydroxyphenyl)-2H-benzotriazoles of the formula STR1 in which X is halogen, R1 is hydrogen, C1 -C12 alkyl, C5 -C6 cycloalkyl, phenyl or phenyl-C1 -C4 alkyl and R2 is C1 -C12 alkyl, C5 -C6 cycloalkyl, phenyl, phenyl-C1 -C4 alkyl or a group --Cn H2n --COOR3, in which n is 0 to 4 and R3 is hydrogen or C1 -C12 alkyl, can be prepared particularly advantageously by catalytic hydrogenation of a corresponding o-nitroazo compound in the presence of a hydrogenation catalyst consisting of 0.1 to 3% of Pt on a support and of an organic amine.
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- Method for preparing 2-phenylbenzotriazoles and 2-phenylbenzotriazole-N-oxides
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A method for preparing a 2-phenylbenzotriazole of formula I wherein R1 is H, Cl, C1-4alkyl, C1-4alkoxy, COOH or SO3H; R2 is H, Cl, C1-4alkyl or C1-4alkoxy; R3 is H, Cl, C1-12alkyl, C1-4alkoxy, phenyl, (C1-8alkyl)phenyl, phenoxy or phenyl(C1-4alkyl); R4 is H, Cl, OH or C1-4alkoxy; and R5 is H, C1-12alkyl or phenyl(C1-4alkyl), comprises reducing a nitroazobenzene of formula III = wherein R1, R2, R3, R4 and R5 are as defined above, with a saccharide in the presence of a hydrogen transfer catalyst and base. This method can be conducted in one or two steps. The individual steps, the first from the nitroazobenzene to a 2-phenylbenzotriazole-N-oxide of formula II and the second (II→I) are independent aspects of the invention.
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- Method for preparing 2-phenylbenzotriazoles and 2-phenylbenzotriazole-N-oxides
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This invention relates to a method for preparing a 2-phenylbenzotriazole of formula I, STR1 (wherein R1 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, a lower alkoxyl group having a carbon number of 1 to 4, carboxyl group, or sulfonic acid group; R2 represents hydrogen or chlorine atom, a lower alkyl group having a carbon number of 1 to 4, or a lower alkoxyl group having a carbon number of 1 to 4; R3 represents hydrogen or chlorine atom, an alkyl group having a carbon number of 1 to 12, a lower alkoxyl group having a carbon number of 1 to 4, phenyl group, a phenyl group substituted with an alkyl group having a carbon number of 1 to 8, phenoxy group, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4; R4 represents hydrogen or chlorine atom, hydroxyl group, or a lower alkoxyl group having a carbon number of 1 to 4; and R5 represents hydrogen atom, an alkyl group having a carbon number of 1 to 12, or a phenylalkyl group, the alkyl part of which has a carbon number of 1 to 4), which comprises reducing an o-nitroazobenzene of formula III, STR2 (wherein R1, R2, R3, R4 and R5 are as defined above) with an aldehyde reducing agent in the presence of an aromatic ketone catalyst and base. This invention further relates to a method for preparing a 2-phenylbenzotriazole of formula I as derfined above, which comprises reducing 1 mole 2-phenylbenzotriazole-N-oxide of formula II, STR3 (wherein R1, R2, R3, R4 and R5 are as defined above) with 1 to 4 mole aldehyde in the presence of an aromatic ketone catalyst and base. This invention still further relates to a method for preparing a 2-phenylbenzotriazole-N-oxide of formula II as defined above, which comprises reducing 1 mole o-nitroazobenzene of formula III as defined above with 1 to 2 mole aldehyde in the presence of an aromatic ketone catalyst and base.
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- Method for preparing 2-phenylbenzotriazoles and 2-phenylbenzotriazole-N-oxides
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A method for preparing a 2-phenylbenzotriazole of formula I wherein R1 is H, Cl, C1-4alkyl, C1-4alkoxy, COOH or SO3H; R2 is H, Cl, C1-4alkyl or C1-4alkoxy; R3 is H, Cl, C1-12alkyl, C1-4alkoxy, phenyl, (C1-8alkyl)phenyl, phenoxy or phenyl(C1-4alkyl); R4 is H, Cl, OH or C1-4alkoxy; and R5 is H, C1-12alkyl or phenyl(C1-4alkyl), comprises reducing a nitroazobenzene of formula III wherein R1, R2, R3, R4 and R5 are as defined above, with an aldehyde, in the presence of an aromatic ketone and base. This method can be conducted in one or two steps. The individual steps, the first from the nitroazobenzene to a 2-phenylbenzotriazole-N-oxide of formula II and the second (II→I) are independent aspects of the invention.
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- Piperidine derivatives, their production and use as stabilizers
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The present invention relates to a piperidine derivative represented by the general formula (I), STR1 wherein R1 and R2 independently represent a hydrogen atom or a C1 -C3 alkyl or C2 -C20 acyl group, R3 represents a hydrogen atom or a C1 -C20 alkyl, C6 -C20 aryl, C7 -C20 aralkyl or C2 -C20 acyl group, and l represents 1 to 3, and a stabilizer for organic substances containing said piperidine derivative as an effective ingredient.
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- Preparation of 2-(2H-Benzotriazol-2-yl)phenols by the Reduction of 2-phenols with Thiourea S,S-Dioxide
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The reduction of 2-phenols 1 with thiourea S,S-dioxide and sodium hydroxide in a mixture of isopropyl alcohol and water at reflux provides 2-(2H-benzotriazol-2-yl)phenols 3 in excellent yields.
- Tanimoto, Shigeo,Kamano, Takayoshi
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p. 647 - 649
(2007/10/02)
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- The Reduction of Some o-Nitrophenylazo Dyes with Glucose: A General Synthesis of 2-Aryl-2H-benzotriazole 1-Oxides
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The reduction of some representative o-nitrophenylazo dyes in ethanolic alkali with glucose gives the corrsponding 2-aryl-2H-benzotriazole 1-oxides in excellent yield.These 1-oxides are rapidly reduced to the parent benzotriazoles at room temperature by means of zinc dust/ethanolic alkali.This method provides a convenient preparation for 5-chlorobenzotriazoles, which are otherwise readily dechlorinated by zinc dust under more vigorous conditions
- Rosevear, Judi,Wilshire, John F. K.
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p. 2089 - 2093
(2007/10/02)
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- Process for the preparation of 2-aryl-2H-benzotriazoles
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A process for producing benzotriazoles of the formula I STR1 wherein R1 is hydrogen or chlorine, R2 is hydrogen, chlorine, C1 -C4 alkyl, C1 -C4 alkoxy, C2 -C9 alkoxycarbonyl, carboxyl or sulfo, R3 is C1 -C12 alkyl, C1 -C4 alkoxy, phenyl, (C1 -C8 alkyl)-phenyl, C5 -C6 cycloalkyl, C2 -C9 alkoxycarbonyl, chlorine, carboxyethyl or C7 -C9 phenylalkyl, R4 is hydrogen, C1 -C4 alkyl, C1 -C4 alkoxy, chlorine or hydroxyl, and R5 is hydrogen, C1 -C12 alkyl, chlorine, C5 -C6 cycloalkyl or C7 -C9 phenylalkyl, which process comprises treating a benzotriazole-N-oxide of the formula II STR2 wherein R1, R2, R3, R4 and R5 have the above meanings, at a temperature of 20°-150° C., with an amine; or treating an o-nitroazobenzene of the formula III STR3 wherein R1, R2, R3, R4 and R5 have the above meanings, at a temperature of 20°-150° C., with an amine.
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- Process for the preparation of 2-aryl-2H-benzotriazoles
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A two stage reductive ring closure of o-nitrophenylazophenols produces 2-aryl-2H-benzotriazoles by (a) reacting an organic solvent solution of azophenol with an excess of an aqueous solution of a sulfhydrate or sulfide to form an N-oxide and (b) reducing the N-oxide with an alkali metal hydroxide plus zinc or tin.
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- Process for the production of 2-aryl-2H-benzotriazoles
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A process for the production of 2-aryl-2H-benzotriazoles comprises reducing and cyclizing the corresponding o-nitroazobenzenes with hydrogen at a temperature in the range of about 20° C. to about 100° C. and at a pressure in the range of about 15 psia (1 atmosphere) to about 1000 psia (66 atmospheres) in an organic solvent mixture containing an organic amine at a pH over 10 in the presence of noble metal hydrogenation catalyst, preferably palladium. High yields of pure product are obtained with a concomitant reduction of undesired by-products and a reduction in effluent pollution problems.
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- 1-Aza-4-thiacyclohexane-4,4-dioxide derivatives
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New 1-aza-4-thiacyclohexane-4,4-dioxide derivatives are used alone or in combination with other stabilizers for stabilizing organic materials. The new compounds are prepared by reacting substituted diallylsulfides with ammonia, amines or hydrazines.
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