(Department of chemistry, Shanghai Normal University, Shanghai, 200234, China) Received June15, 2003; Supported by the Natural science of Shanghai (No. 2000D07) Abstract This communication reports the synthesis, crystal structure and the herbicidal activity of 1-Benzoyl-3-(4,6-disubstitute-pyrimidine-2-yl)-thiourea. The structures of the five target compounds were determined by IR, 1H NMR and MS.Keywords crystal structure, herbicidal activity, 1-benzoyl-3-(4,6-disubstitute- pyrimidine-2-yl) -thiourea Pesticides form a major proportion of the
total agrochemicals production and usage. Approximately 4.5×109 pounds of
pesticides are used in a typical year only in USA[1]. Many acyl thiourea
compounds have been widely studied for their insecticidal, antibacterial and pesticidal
activities and promoting effect on plant growth[2-4]. These have attracted the
attention of many investigators. A series of new
1-benzoyl-3-(4,6-disubstitute-pyrimidin-2-yl)-thioureas derivatives have been synthesized
in this paper. Further, the crystal structure of Bdpt
[1-Benzoyl-3-(4,6-dimethyl-pyrimidin-2-yl)-thiourea] were determined by X-ray and its
herbicidal behavior were investigated.
1. EXPERIMENTAL SECTION Preparation of the single crystal of the target molecule : Its single crystal, suitable for X-ray analysis, grows from the mixed solvent of methanol and acetonitrile(1:2)by slow evaporation for 4 day. 1.4 Characterization Data for the Products Compound (a): Yield: 85%; m.p: 196-197oC; IR(cm-1):2900,3100(N-H),1710(C=O),1240(C=S),1600(C=N).1HNMR(d:ppm):2.40(s,6H,2CH3),6.72(s,1H,Py-5-H),7.42(m,5H,Ph-H). MS (m/z): 51(83), 77(97), 105(100), 149(89), 181(42), M+286(75). Compound (b): Yield: 75%; m.p: 196-198oC; IR (cm-1): 2950,3150(N-H), 1720(C=O), 1240(C=S), 1600(C=N). 1HNMR(d:ppm):2.40(s,3H,CH3),3.92(s,3H,OCH3),6.28(s,1H,Py-5-H), 7.25(m,5H, Ph-H). MS (m/z): 51(74), 77(99), 105(100), 165(18), 197(5), M+302(7). Compound (c): Yield: 87%; m.p: 182-183oC; IR (cm-1): 3000,3350(N-H), 1710(C=O), 1250(C=S), 1600(C=N).1HNMR(d:ppm):1.33(t,3H,OCH2CH3),2.52(s,3H,CH3),4.29(q,2H,OCH2CH3), 6.26 (s,1H,Py-5-H),7.49(m,5H, Ph-H). MS (m/z): 51(82), 77(100), 105(98), 181(26), 213(4), M+318(14). Compound (d): Yield: 65%; m.p: 197-198oC; IR (cm-1): 3000,3150(N-H), 1720(C=O), 1230(C=S), 1600,1580(C=N). 1HNMR(d:ppm):4.10(s,3H,OCH3),6.64(s,1H,Py-5-H),7.50(m,5H, Ph-H). MS (m/z): 51(83), 77(99), 105(100), 185(11), 217(2), M+322(8), [M+2]+324(3) Compound (e): Yield: 54%; m.p: 164-165oC; IR (cm-1): 2950,3150(N-H), 1710(C=O), 1240(C=S),1590(C=N).1HNMR(d:ppm):1.40(t,6H,N(CH2CH3)2),3.60(t,4H,N(CH2CH3)2),6.08(s,1H,Py-5-H),7.50(m,5H, Ph-H). MS (m/z): 51(81), 77(99), 105(100), 226(6), 258(2), M+363(4), [M+2]+365(1) 2. X-RAY CRYSTAL STRUCTURE
DETERMINATION Figure 2 The packing crystal cell of target molecula Data Figure2 demonstrates that the molecular structures form dimer compounds through intermolecular hydrogen bond .The bond carbonyl group C(2)=S form intramolecular hydrogen bond with N(2), whereas atom N(1) interacts with N(4) of the pyrimidine ring by intramolecular hydrogen . It should be stressed that these hydrogen bonds might possibly suggest the relation with herbicide activities by binding the site which block the transfer of electrons from the electron donor to the electron carriers. 3. HERBICIDAL EFFICIENCY The preliminary biological tests showed that the Bdpt has excellent inhibitory activities against broad leaf (such as Amaranthus retroflexus L), meanwhile, it has part selectivity on monoctyledon plant(such as Echinochloa Crusgauis(L)). Table 1. The Inhibition Percentage of Bdpt to kinds of weeds
Acknowledgements REFERENCES [2] Noguchi T, Ohkuma K, Kosaka S. Proceeding of the 2nd International IUPAC Congress of Pesticide Chemistry, New York, 1972, 5, 263. [3] Ramadas K, Svinivasan N. Synth. Commun, 1995, 25 (2D): 338. [4] Lieb F, Philip U C. Chem. Plant Prot, 1994, 10: 189 (C.A.1995,122:153983k) [5] Jin Shan Zhou, Si Jia Xue. J.Central China Norm.Univ.(Nat.Sci), 1999, 33(1): 233-237. 1-苯甲酰基-3-(4,6-二取代嘧啶-2-基)硫脲衍生物的合成、晶体结构和除草活性 薛思佳 段李平* 柯少勇 贾良斌 (上海师范大学 生命与环境科学学院 化学系 上海 200234 ) 摘 要 本文报道了1-苯甲酰基-3-(4,6-二取代嘧啶-2-基)硫脲衍生物的合成、晶体结构和除草活性。标题化合物的结构经IR, 1H NMR和MS得到确证。其中对化合物1-苯甲酰基-3-(4,6-二甲基嘧啶-2-基)硫脲进行了单晶衍射,使其结构得到进一步确证。 关键词 1-苯甲酰基-3-(4,6-二取代嘧啶-2-基)硫脲,合成,晶体结构,除草活性 |
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