Syntheses and Crystal Structures of Methyl 2-(4,5-Dibromo-1-methylpyrrole-2-carbonylamino)-3-phenylpropanoate and 4,5-Dibromo-1-methyl-2- trichloroacetylpyrrole

4,5-Dibromo-1-methyl-2-trichloroacetylpyrrole Ⅰ, prepared by the reaction of 1-methyl-2-trichloroacetylpyrrole with Br2 in 98.6 % yield, was condensed with methyl L-2-amino-3- phenylpropanoate to afford methyl 2-（4,5-dibromo-1-methylpyrrole-2-carboxmido）-3-phenylpropanoate Ⅱ in 90.8% yield. Crystal data for Ⅰ： monoclinic system, space group P21/c with a = 8.595（3）, b = 10.900（4）, c = 12.321（5） ,A°,β = 92.292（7）°, V = 1153.4（8）A°^3, Dc = 2.213 g/cm^3, F（000） = 728, CTH4Br2Cl3NO, Mr = 384.28, λ = 0.71073 A°, μ（MoKa） = 7.688 mm^-1, Z = 4, R = 0.0338 and wR2 = 0.0840 for 1963 observed reflections with I 〉 2a（I）. Crystal data for Ⅱ： monoclinic system, space group P21 with a = 4.886（2）, b = 15.921（8）, c = 11.635（6） A°,β = 101.803（9）°, V = 885.9（7） A°^3, Dc = 1.665 g/cm^3, F（000） = 440, C16H16Br2N2O3, Mr = 444.13, λ = 0.71073 A°, μ（MoKa） = 4.590 mm^-1, Z = 2, R = 0.0335 and wR2 = 0.0837 for 3191 observed reflections with I 〉 2σ（I）. The crystal structure reveals that compound Ⅱ forms the one-dimensional chain structure via the intermolecular hydrogen bonds of N（2）-H…O（1）.

Synthesis and Crystal Structure of N-[(2S)-4-bromo-2-(L-menthyloxy)-5-oxo-2,5-dihydro-3-furyl]-L-leucine

Starting from（5S）-（L-menthyloxy）-3,4-dibromo-5H-furan-2-one and L-leucine,the title compound N-[（2S）-4-bromo-2-（L-menthyloxy）-5-oxo-2,5-dihydro-3-furyl]-L-leucine 5（C20H32BrNO5,Mr = 446.37） was obtained in one-pot process via the tandem Michael addition-elimination reaction in the presence of potassium hydroxide.The chemical structure and absolute configuration of the title compound were confirmed via rotation,UV-Vis,FT-IR,1H NMR,13C NMR,MS and elemental analysis,especially by the X-ray single-crystal diffraction.The crystal crystallizes in an orthorhombic system,space group P212121 with a = 12.5249（16）,b = 19.005（3）,c = 19.719（3） ,V = 4693.7（10） 3,Z = 8,Dc = 1.263 g/m3,μ = 1.778 mm-1,F（000） = 1872,the final R = 0.0617 and wR = 0.1576 for 3967 observed reflections（I 2σ（I））.X-ray analysis reveals that the title compound has two independent molecules in the asymmetric part of the unit cell with the two five-membered furanones being almost planar.The essential part of the electron delocalization is concentrated in the N（1）,C（3）,C（1）,C（37） and O（7） region and N（2）,C（28）,C（27）,C（30） and O（4） region in the other molecule respectively,but does not take place at the expense of delocalization within the ester function.

Mitigating microbiologically influenced corrosion of an oilfield biofilm consortium on carbon steel in enriched hydrotest fluid using 2,2-dibromo-3-nitrilopropionamide(DBNPA) enhanced by a 14-mer peptide

In the oil and gas industry,microbiologically influenced corrosion(MIC) is a major threat to hydrotest,a procedure which is required to certify whether a pipeline can be commissioned.Seawater is frequently used as a hydrotest fluid.In this bio film prevention lab study,an oilfield biofilm consortium was grown in an enriched artificial seawater anaerobically at 37℃ for 60 days.The combination of 100 ppm(w/w) 2,2-dibromo-3-nitrilopropionamide(DBNPA)+100 nM(180 ppb) Peptide A(a biofilm dispersal agent) led to extra SRB(sulfate reducing bacteria),APB(acid producing bacteria) and GHB(general heterotrophic bacteria) sessile cell count reductions of 0.9-log,0.8-log and 0.6-log,respectively,compared with the outcome obtained by using 100 ppm DBNPA only.The Peptide Aenhancement also led to extra reductions of 44 % in weight loss,43 % in maximum pit depth,and 54 % in corrosion current density.