investigations on the offensive odour of hemiptra-bugs

investigations on the offensive odour of hemiptra-bugs 文库 手机文库 Investigations on the offensive odour of hemiptra-bugs Tetrahedron Printed in Great Britain. Letters No.22, pp. 2479-2481, 1966, Pergsmon Press Ltd. INVESTIGATIONS ON THll OFFENSIVE ODOUR OF IIEMIP’PRA-BUGS S.K. Mukerji* and H.L. Sharma** Department of Chemistry, University of Rajasthan, Jaipur(India). (Received JO March 1966) Blaok Hemiptra Bugs(Fam:Pentatomidea;Hindi:Tehlen) generally observed immediately after the rainy season, especially in the tropical regions of the country, whenever disturbed or crushed give off a characteristic nauteating smell. The oompound due to which the bugs possess this obnoxious smell has been obtained in the form of a colour- less oil. Its structure has been assigned on the basis of 1.R. studies and its synthesis. Bugs (24 g.), colledted soon after their death, were successively extracted in a soxhlet extractor with petroleum ether (40-60.) for 26 hrs. Most of the solvent from the extract was removed by distillation under reduced pressure and the remainder extract (oa 15 ml.) was shaken well with aq. methanol (I:1 v/v). The petroleum ether layer containing the fatty matter was thus separated from the aq. methanolic Present Address: *Geological Survey of India, Rajasthan Circle, Jaipur (India) **Department of Pharmacology, S.M.S. Medical College, Jalpur (India). 2479 24so No.22 layer containing the compound, which was purified by direct distillation a6 a oolourleoo oil (0.9 g.), b.p. 112-113a. Micro quantities of the oil when subjected to qualitative tests failed to respond for N, S or halogens. 0.4 g. of the 011 when dir8olved in methanol and treated with methsnolic solution Of 2,4-dinitrophenylhydrarine immediately resulted In an orange ppt 关于艾滋病ppt课件精益管理ppt下载地图下载ppt可编辑假如ppt教学课件下载triz基础知识ppt . lndloatlng the presence of a carbonyl group. Thlm mdrazone was found to be homogeneous on thin layer ohromatography (Silica Gel 0, activated at llO* for 24 hre.) using benzene:ethanol (131 v/v, purified before use by rtandard methods). That this oil poasesaes an aldehydic group is exhibited by it8 positive test for Tollen’s reagent and Fehling’s soln. and also by ito I.R. studies which shows peaks (1) at 975 0;’ (tranr-C=C-), 1380 o?(-C-Me), and at 1725 cE’ (-CHO). On the baolr of these studies and the microanalysis report the rtruoture of the aldehyde has been assigned as trans-l-hepten- l-al; CHSCH2Cli=CBCH2C&$XlO. (Found: C, 75.02; H, 10.62; . Mol.wt.(Rast),ll4. Calo. for C,Hi20r C, 75.00: R, 10.71% MOl.wt.112.) Ita 2,4-dinltrophenylhydraeone obtained as described above was orystallised from ethanol in dull orange needles (1 go) m.p. 120.. (Found: C, 53.33; H, 3.96; N, 19.02. Mol.wt.(Rast), 290. Calc. for,Ci3 i5 4 4 H 0 N I C, 53.42; H, 4.10; N, 19.17%. Mol.wt. 292). Its structure was further oonfirmed by comparing its 1-R. 8pectrogram with that of the synthetic sample obtained by the No.22 2461 method already reported(Z). Thus pent-I-en-3-01, obtained bF treating vinyl magneeium bromide with propionaldehyde raa converted into Its vinyl ether(3) by mercuric acetate catalysed tm-etherification with ethyl vinyl ether. The vinyl ether thus obtained when subjected to the Claisen rearrangement(4) furnished m-4-hepten-I-al(2) in 70% yield. b.p. 112-113.. (Found: C, 74.92; H, 10.55. Calc. for C,Hi20: C, 75.00, H,10.71%.) The 2,4-dinitrophenylhydrazone was crystallised from ethanol in dull orange needles m.p. 120?. (Found: C, 53.39; H, 3.99; N, 19.01..Calc. for C13H1604N4: C, N, 19.17$.) (Elixed m.p. of 文库 手机文库 文库 手机文库 both the samples undepressed). 53.42; H, 4.10; remains ACKNO~LEDCR?~’:TS 1 . Authors’ sincere thanks are due to Dr. R.C. Mehrotra, Prof. & Head of the Department of Chemistry, University of Rajasthan, Jaipur for providing necessary facilltiee. R!:FEl’.ENCES I. Cross, Introduction to Practical Infrared Suectroaoony; p 58-64, Butterworths, London (1964). 2. 0.P. Vig, Baldev Vig, Ajaib Sin J. Indian. Chea. Sot. 43 637, $ h and Inder Raj, 1965) 3. O.P. Vlg, K.L. Yatta and Inder Raj, lhid 4& 762(1964) 4. A.K. Burgstahler, J. Amer. Chem. Sot. &4681(1960) 文库 手机文库