Synthesis of some new 3-[5-(2-oxo-2H-3-chromenyl)-1,3-oxazol-2-yl]-1,3-thiazolan-4-ones as antimicrobials

A series of some new 2-imino-5-[（Z）-1-（4-methylphenyl）methylidene]-3-[5-（2-oxo-2H-3-chromenyl）-1,3-oxazol-2-yl]-1,3- thiazolan-4-ones 5a-j has been synthesized and assayed for their antibacterial activity against Gram-positive bacteria viz.Bacillus subtilis（ATCC 6633）,Staphylococcus aureus（ATCC 6538p） and Micrococcus luteus（IFC 12708）,and Gram-negative bacteria viz. Proteus vulgaris（ATCC 3851）.Salmonella typhimurium（ATCC 14028） and Escherichia coli（ATCC 25922）.Among the screened compounds,5d,5e,5f,5g,and 5j exhibited potent inhibitory activity compared to standard drug,and emerged as potential molecules for further development.

Regioselective Ring-opening Reaction of 1,2-Epoxides with Arylselenol under Solvent-free Conditions and Application to the Synthesis of 1,3-Oxazolidin-2-ones

Regioselective ring-opening reactions of 1,2-epoxides with ArSeH catalyzed by Ti（O^tPr）4 under solvent-free conditions were investigated. A variety of β-hydroxyselenides were obtained in excellent yields of 90%-97% and regioselectivities by a simple, atom economic and environment-friendly procedure. Several N-tosyl- 1,3-oxazolidin-2-ones were prepared starting from the corresponding 1,2-epoxides and ArSeH by a one-pot three-step procedure.

Syntheses and Crystal Structures of Cobalt(II) Chloride Complexes of 1,3-Bis(pyridyl-4-ylthio)propan-2-one

Reactions of 1,3-bis（pyridyl-4-ylthio）propan-2-one L and COCl2·6H2O under different conditions gave two new cobalt（Ⅱ）-chloride-L complexes with distinct structures. Complex [Co（L）2Cl2]·0.5CH3OH}n 1 prepared by solvothermal treatment is a 3D network, whereas complex {[Co3（L）2Cl6（DMF）4]·2CH3OH·H2O} 2 obtained in DMF-diethyl ether system is a discrete acyclic trimer. Crystal data for 1： space group lbca, a = 15.993（4）, b = 18.454（5）, c = 21.506（6）A, V= 6347（3） ,A^3, Z = 8, Dc = 1.462 g/cm^3,μ = 1.005 mm^-1, F（000） = 2864, C26.5H26Cl2CoN4O2.5S4, Mr = 698.58, the final R = 0.0499 and wR = 0.1024. Crystal data for 2： space group P1^-, a = 9.9177（6）, b = 11.0871 （4）, c = 15.5490（12） ,A, α = 83.1834（14）,β = 88.910（13）, γ = 71.096（ 11 ）°, V = 1605.8（2） A^3, Z = 1, Dc = 1.362 g/cm^3,μ= 1.194 mm^-1, F（000） = 677, C40H62Cl6Co3N8O9S4, Mr = 1316.71, the final R = 0.0666 and wR =0.1575.

2-Thioxo-1,2-dihydrobenzo[d][1,3]thiazin-4-one:Synthesis,Crystal Structure and Its Photoinduced Proton Transfer Reaction

2-Thioxo-1,2-dihydrobenzo[d][1,3]thiazin-4-one （TDBTO）, a new thiazin-one derivative, was synthesized and investigated. The crystal structure of TDBTO （CsHsNOS2, Mr = 193.8） was determined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 6.946（3）, b = 7.402（3）, c = 8.954（4）A, α = 66.931（7）°,β = 89.866（7）°, γ = 72.289（7）°, V = 399.8（3） A^3, Z = 2, Mr = 195.25, Dc = 1.622 g/cm^3,μ = 0.606 mm^-1, F（000） = 200, R = 0.0361 and wR = 0.1032. There exist intermolecular hydrogen bond of N（1）-H（1A）-..O（1） and weak C（6）-H（6A）...O（1） contact in the structure as well as face-to-face π-π stacking interactions between the benzene ring and the thiazin ring of an adjacent benzothiazin unit. The photoinduced proton transfer reaction, transforming the initial thione into thiol form, was found, and the latter form was characterized by UV absorption spectra, fluo-rescence spectra and infrared spectra.

An efficient synthesis of imidodicarbonic diamides from 1,3-thiazetidin-2-ones with NH_2OH·HCl via ring-opening reaction

A ring-opening process of 4-imino-1,3-thiazetidin-2-ones with NH2OH.HCI was described for the first time. Two different scaffolds of imidodicarbonic diamide were obtained selectively in good yields in the presence of organic base. The obtained imidodicarbonic diamides were demonstrated by X-ray diffraction analysis.

Intermolecular[4+2]process of N-acyliminium ions with simple olefins for construction of functional substituted-1,3-oxazinan-2-ones

An efficient approach to functionalized 4,6-disubstituted-and 4,6,6-trisubstituted-1,3-oxazinan-2-ones skeleton has been developed through the reaction of semicyclic N,O-acetals 4a and 4b with 1,1-disubstituted ethylenes 5 or 8.As a result of such a[4+2]cycloaddition process,4,6,6-trisubstituted-1,3-oxazinan-2-ones 6aa,6af-6au,7ba,7bf-7bw and 6,6-spiro containing 1,3-oxazinan-2-ones 9ad,9ae,10ba-10bg were obtained in 36%-96%yields and with moderate to excellent diastereoselectivities.In addition,the synthesis of(±)-norallosedamine 12 could be conveniently achieved from the cycloadduct 7bf.

Phosphine oxide-Sc(OTf)3catalyzed enantioselective bromoaminocyclization of tri-substituted allyl N-tosylcarbamates

Phosphine oxide-Sc(OTf)3 catalyzed regio-and enantioselective bromoaminocyclization of tri-substituted allyl N-tosylcarbamates is described. Awide variety of optically active tertiary 5-bromo-1,3-oxazinan-2-ones can be obtained with high regio-and enantioselectivity.

UPLC-Q/TOF法同时定性定量分析滇芹药材中主要化学成分

目的建立UPLC-Q/TOF法同时定性、定量分析滇芹中主要化学成分。方法采用超高效液相色谱串联飞行时间质谱法进行分析,色谱柱为Agilent Poroshell 120 Hilic,流动相为乙腈-0.1%甲酸水溶液,梯度洗脱,体积流量0.3 m L/min;定性、定量采用Q-TOF正负离子全扫描+IDA(信息关联采集)模式。结果利用已建立的筛查数据库将满足质量误差小于5×10-6、同位素分布正确且含有二级碎片的离子作为分析目标化合物,结合软件Formula Finder、Mass Calculators等功能、在线数据库(Human Metabolome Database、Pub Chem、Chemical Book等)及二级碎片裂解规律,共鉴定出23个化合物,滇芹首次发现4个化合物。确定阿魏酸为定量分析指标性成分,其定量、定性离子分别为178和149;阿魏酸检测质量浓度线性范围为1.14~1 140 ng/m L(r=1.000),检测限、定量限分别为0.87、2.91 ng/m L,精密度、稳定性、重复性试验的RSD<2%,加样回收率为98.13%~101.25%(RSD=1.37%,n=5)。结论该方法灵敏度高、重现性好,分析快速、准确、可靠,可用于同时定性、定量检测滇芹药材中主要化学成分;云南滇芹中阿魏酸含量要高于西藏滇芹。