University of Groningen Cyclische seleniumverbindingen Winter, Harm Jan IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Publisher's PDF, also known as Version of record Publication date: 1937 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Winter, H. J. (1937). Cyclische seleniumverbindingen. M. De Waal. Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license. 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SUMMARY OF RESULTS. the yields of selenacyclobutane com mides are much higher, if the hy This thesis describes the preparation of selenacyclobutanes central carbon are replaced by larg( (rings composed of one selenium and three carbon atoms) by the cyclobutane ring is easily formed i interaction of alcoholic potassium selenide and trimethylene bromides similar ring or with a cyclohexane with a quarternary central carbon atom. The substituted selenacyclobutan l Potassium selenide and 1,3-dibromopropane give a poor yield of more stable than se\enacyclobutane selenacyclobutane. The main reaction product is a polymeride 1). 2,6_Diselena-4-spiroheptane is , Tetrabromotetramethylmethane, 2,2-dimethyl-1 ,3-dibromopropane m.p. 67° C. The crystals are isomo and I, I-dibromomethylcyclohexane react with potassium selenide, gous sulphur compound, dithiasp giving a good yield of 2,6-diselena-4-spiroheptane (I), 3,3-dimethyl­ cyclobutane (b.p. 56°140 mm; 138­ selenacyclobutane (I I) and 2-selena-4-spirononane (III). 4-spirono nane (b.p. 103.5-104°1 liquids with a pungent odour, whic 2 Se CH)C <CH2" ,)Se CH;3) C<CH "'se as that of selenacyclobutane. < CH CHz/ CH 3 CH~ 2_Phenyl-2-methyl-l,3-dibromop (I) (Il) that it reacted readily at room temr These bromides only react with an alcoholic solution of potassium The main product was a hydrocal selenide on heating, whereas trimethylene bromide does so at room bye-product 4-plzenyl-4-metlzyl-I,2. temperatu reo 114.5°, IV). The constitution of tl Tetrabromotetramethylmetllane is 75 % converted, when boiled oxidation to 2-phenyl-2-methylpro for half an hour with alcoholic potassium selenide, a polymeride not connection a statement of Franke being formed. It is difficult to separate the product, 2,6-diselena­ methyldibromopropane the bromim 4-spiroheptane from unchanged tetrabromotetramethylmethane; the in aliphatic dialkyltrimethylene br( purification by means of the additive compound with mercuric 4,4-Dimethyl-I,2-diselenacyclop chloride causes great losses. from 2,2-dimethyl-I,3-dibromopro 2,2-Dimethyl-I,3-dibromopropane is completely converted by diselenocyanate. boiling it for four hours with alcoholic potassium selenide, and a C6H <CH2-se O')C 1 (IV) 40 % yield of 3,3-dimethylselenacyclobutane can be isolated from CH3 CHz-Se the reaction mixture. These two diselenacyclopentam l,l-Di-bromomethyl-cyclohexane is prepared from the cor­ ferent organic solvents as browl responding diol and phosphorus tribromide. It reacts with alcoholic pleasant, pungent odour. potassium selenide more slowly than dimethyldibromopropane, but The compounds prepared by u: 2-selena-4-spirononane (I II) nevertheless was obtained in excellent and thus show residual affinity. 1 yield (68 % ) . Thus, as with thiacyclobutane and 3,3-dimethyIthiacyclobutane, reagents were studied. 1) Morgan and Burstall, J. Chem. Soc. 1930, 1497. 1) Franke, Monatsh. 34, 1895 (191 3 69 OF RESULTS. the yields of selenacyclobutane compounds from trimethylene bro­ mides are much higher, if the hydrogen atoms attached to the ~paration of selenacyclobutanes central carbon are replaced by large groups. Moreover, the selena­ and three carbon atoms) by the cyclobutane ring is easily formed in spirocyclic connection with a elenide and trimethylene bromides atom. similar ring or with a cyclohexane ring. The substituted selenacyclobutane compounds thus obtained are )mopropane give a poor yield of more stable than selenacyclobutane itself. ion product is a polymeride 1). 2,6-Diselena-4-spiroheptane is a white, crystaHine compound, ,2-dimethyl-l,3-dibromopropane m.p. 67° C. The crystals are isomorphous with those of the analo­ react with potassium selenide, gous sulphur compound, dithiaspiroheptane. 3,3-Dimethylselena­ '-spiroheptane (I), 3,3-dimethyl­ cyclobutane (b.p. 56°/40 mm; 138-138.5°/750 mm) and 2-selena­ a-4-spirononane (III). 4-spirononane (b.p. 103.5-104°/1 3 mm) are stable, colourless 2 liquids with a pungent odour, which, however, is not so nauseating >Se /CH -CH2) (CH) CH2, C Se as that of selenacyclobutane. , CHz-CH2 CH_ (III) 2-Phenyl-2-methyl-l,3-dibromopropane behaved differently, in that it reacted readily at room temperature with potassium selenide. i alcoholic solution of potassium The main product was a hydrocarbon C1oH12, accompanied by a ylene bromide does so at room bye-product 4-p/1 enyl-4-methyl-l,2-diselenacyclopentane (m.p. 114­ 114.5°, IV) . The constitution of this compound was confirmed by 75 % converted, when boiled oxidation to 2-phenyl-2-methylpropane-l,3-diseleninic acid. In this ,ium selenide, a polymeride not connection a statement of Franke 1) is of interest, that in phenyl­ rate the product, 2,6-diselena­ methyldibromopropane the bromine atoms are bound less firmly than bromotetramethylmethane; the in aliphatic dialkyltrimethylene bromides. rive compound with mercuric 4,4-Dimethyl-l,2-diselenacyclopentane (m.p. 34°, V) is obtained from 2,2-dimethyl-I,3-dibromopropane through the corresponding is completely converted by diselenocyanate. ilic potassium selenide, and a C6H5) < CH 2- se CHS·)· / CH2-Se obutane can be isolated from C I (IV) C I (V) CH" CH2-Se CH3 "'CH2- Se s prepared from the cor­ These two diselenacyclopentane compounds crystallize from dif­ lmide. It reacts with alcoholic ferent organic solvents as brown needles or plates with an un­ dimethyldibromopropane, but pleasant, pungent odour. less was obtained in excellent The compounds prepared by us contain bivalent selenium atoms, and thus show residual affinity. The addition reactions with several 3,3-dimethylthiacyclobutane, reagents were studied. 930, 1497. 1) Franke, Monatsh. 34, 1895 (1913) . 7 70 If the sodium salts of these aci( 2,6-Diselena-4-spiroheptane gives an addition compound with sodium ha'lide is precipitated, and two mols. mercuric chloride, and with iodine it gives an unstable The selenone 3,3-dimetllylsele tetraiodide. obtained by oxidation of 3,3-dime With an excess of methyl iodide a crystalline monoselenium com­ oxide. Oxidation of 4-phenyl-4-m pound is formed : 4,4_dimethyl-I ,2-diselenacyc1oper - se< CH2""c< cH2se(CHsh-1 I the following seleninic acids: 1_ CH~ CH 2I _ 2,2_dimethylpropane-I,3-diseh The behaviour of 3,3-dimethylselenacyc1obutane and 2-selena-4­ (CH 3)zC(1 spirononane with several reagents is almost similar. Mercuric 2_phenyl-2-metl1ylpropane-l,3 chloride and mercuric bromide furn-ish nearly insoluble addition (CoHa) (CHal compounds. With two molecules of methyl iodide, th e selenacyclo­ These compounds add two butane ring opens. Thus dimethylselenacyc10butane gives crystalline dinitrates. Both diseleninic acid 3-iodo-2,2-dimethyl-propyl-dimethylselenonium iodide. The structure The solubilities of these coml of this compound proved to be: dimethyl derivative being readily (CHa)2C(CH2i) . CH Se(CH:)2 I 2 compound dissolves sparingly a With excess of chlorine or bromine the selenacyc10butane ring water. By the recrystallization also opens and tetra halides are formed : dinitrate from hot water, the di soluble than the diseleninic acid RR'C( . CH 2 · )zSe + 2 HI gz = RR'C(CHzHIg) (CH2SeHIg) of phenylmethylpropanediselenir These halides dissolve in water, yielding acid solutions. The acid, being less soluble than the necessary quantity of silver hydroxide COil verts them into the By the interaction of 2,2-din corresponding seleninic acids. Jn this way the following seleninic bromine, a tetrabromide (CHa acids have been obtained. dibromide (CH )2C(CH SeBr) : 3-bromo-2,2-dimethy/propaneseleninic acid: 3 z (CHa) 2C( CH2Br) CHzSeOz H LIST OF NE ' 3-chloro-2 ,2-dimeth ylpropanese/ cninic acid: Cyclic mono- and diselenium (CH3 )zC (CHzCI) CH Z Se02H CH3)C l-bromomethyl-I-metlzylseleninic acid cyclohexane: CH 3 3,3_dimethylselenacyclobutane; t CH.,-CH?,- < CH?Br CH2-C CH CH: _ CH)C CH:se02H CH < CHz-( l-chloromethyl-I-metlzylsclc/linic acid cyclolzexa/le: 2-selena-4-spirononane< CH2 -CH2,,- / CH2CI / Se~H2' CH2 ) C. ""CH 2 - CH2 "-CH2Se02H ~CH 2' All these seleninic acids are white crystalline compounds. 2,6-diselena-4-sI 70 71 (ives an addition compound with If the sodium salts of these acids are heated in alcoholic solution, j with iodine it gives an unstable sodium halide is precipitated, and selenones are formed. The selenone 3,3-dimethylselenacyclobutane-I, I-dioxide is also Ie a crystalline monoselenium Com­ obtained by oxidation of 3,3-dimethylcyclobutane with hydrogen per­ oxide. Oxidation of 4-phenyl-4-methyl-1 ,2-diselenacyclopentane and /CH2Se(CHsh] I 4,4-dimethyl-l,2-diselenacyclopentane with nitric acid (1.30), gives the following seleninic acids: , CH21 2,2-dimethylpropane-I,3-diseleninic acid selenacyclobutane and 2-selena-4­ (CH ) 2 C(CH Se0 H) 2 'nts is almost similar.