Synthesis, Crystal Structure, and Biological Activity of 4-Chlorobenzaldehyde (2-trifluoromethylTrifluoromethyl-5,6,7,8-tetrahydrobenzo[4 ,5]-thieno[2,3-d]pyrimidin-4-yl)hydrazone Monohydrate

The novel title compound 4-chlorobenzaldehyde （2-trifluoromethyl-5,6,7,8- tetrahydro- benzo[4,5]thieno[2,3-d]pyrimidin-4-yl）hydrazone monohydrate （C18H14C1F3N4S.H20, Mr = 428.86） has been synthesized by a condensation reaction of 4-chlorobenzaldehyde with （2-trifuoromethyl-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-yl）hydrazine, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 7.4252（7）, b = 26.344（2）, c = 10.3095（9） A, /3 = 109.407（2）~, V= 1902.0（3） A3, Z = 4, Dc = 1.498 g/cm^3, p = 0.356 mm-1, F（000） = 880, the final R = 0.0564 and wR = 0.1681 for 2343 observed reflections with I 〉 2o（/）. X-ray diffraction analysis reveals that the title hydrazone molecule is nearly planar except for the cyclohexene and trifluoromethyl moieties. In the crystal packing, the molecules form stacks by a three-dimensional framework, which results from intermolecular N（3）-H（3）...O（1）, O（1）-H（1B）...N（2）, O（1）- H（1B）...N（4） and O（1）-H（1A）...F（1） hydrogen bonds via water molecules together with π-π stacking interactions. Molecular geometry of the title compound in the ground state optimized by B3LYP functional with 6-311G＊＊ basis sets indicates that the calculations are in agreement with the experimental data. The preliminary bioassay suggested that the title compound exhibits relatively good fungicidal activity against Fusarium oxysporium fsp.vasinfectum and Dothiorella gregaria.

Syntheses, Crystal Structures, and Biological Activities of Two Enantiomeric 2-Trifluoromethylthieno[2,3-d]pyrimidin-4-amine Derivatives

Two enantiomeric 2-trifluoromethyl-6,7-dihydro-5H-cyclopenta[4,5]thieno[2,3-d] pyrimidin-4-amine derivatives were synthesized by nucleophilic substitution of two chiral amines with 4-chloro-2-trifiuoromethyl-6,7-dihydro-5H-cyclopenta[4~5]thieno[2-3-d]pyrimidine, which started from 2-amino-5,6-dihydro-4H-cyclopenta[b]thiophene-3-carbonitrile, trifluoroacetic acid （TFA） and phosphoryl trichloride via one-pot procedure. Their structures were determined by single-crystal X-ray diffraction. Enantiomer （R）-3,（R）-N-（1-phenylethyl）-2-trifluoromethyl-6,7- dihydro-5H-cyclopenta[4,5]thieno[2,3-d]pyrimidin-4-amine crystallizes in the tetragonal system, space group P43 with a = 8.6847（6）, b = 8.6847（6）, c = 22.419（2） A, V= 1690.9（3） A3, Z = 4, Dc = 1.428 g/cm^3, p = 0.228 mm-1, F（000） = 752, the final R = 0.0463 and wR = 0.1257 for 3442 observed reflections with 1〉 20（/）. Enantiomer （S）-3,（S）-N-（1-phenylethyl）-2-trifluoromethyl-6,7-dihydro- 5H-cycloperita[4,5]thieno[2,3-d]pyrimidin-4-amine crystallizes in the tetragonal system, space group P41 with a = 8.688, b = 8.688, c = 22.421 A, V = 1692.4 A3, Z = 4, Dc = 1.426 g/cm^3, μ= 0.227 mm^-1, F（000） = 752, the final R = 0.0682 and wR = 0.1806 for 3182 observed reflections with ≥20（I）. The preliminary bioassay indicated that the R-enantiomer exhibits higher antitumor activity against MCF-7 than gefitinib.

Syntheses, Crystal Structures, and Antitumor Activities of Two 2-Trifluoromethyl-5,6,7,8-tetrahydrobenzo[4,5]-thieno[2,3-d]pyrimidin-4-amine Derivatives

Two novel 2-trifluoromethyl-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4-amine derivatives were synthesized by nucleophilic substitution of two appropriate amines with 4-chloro-2-(trifluoromethyl)-5,6,7,8-tetrahydrobenzothieno[2,3-d]pyrimidine, which started from 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile, trifluoroacetic acid(TFA) and phosphorous oxychloride by one-pot procedure. Their structures were determined by single-crystal X-ray diffraction. Compound 1, N-(furan-2-ylmethyl)-2-trifluoromethyl-5,6,7,8-tetrahydrobenzothieno[2,3-d]pyrimidin-4-amine, crystallizes in the monoclinic system, space group C2/c with a = 26.352(3), b = 7.5991(8), c = 17.1423(18) A, β = 114.667(2)°, V = 3119.5(6) A3 and Z = 8. Compound 2, N-(3-silatranylpropyl)-2-trifluoromethyl-5,6,7,8-tetrahydrobenzothieno[2,3-d]pyrimidin-4-amine, crystallizes in the monoclinic system, space group P21/n with a = 13.4394(13), b = 8.9446(9), c = 18.9657(18) A, β = 101.9640(10)°, V = 2230.3(4) A3 and Z = 4. The preliminary bioassay indicated that compound 2 exhibits more potent antitumor activity against BCG-823 than 5-fluorouracil(5-FU).

Synthesis, Crystal Structure, and Antitumor Activity of 1-(4-Methoxybenzylidene)-2-(1-phenyl-6-trifluoromethyl-1H-pyrazolo[3,4-d]pyrimidin-4-yl)hydrazine Monohydrate

The novel title compound 1-（4-methoxybenzylidene）-2-（1-phenyl-6-trifluoromethyl- 1H-pyrazolo[3,4-d]pyrimidin-4-yl）hydrazine monohydrate （C20HisF3N60-H20, Mr = 430.40） has been synthesized by a four-step procedure including the cyclization, chlorination, hydrazinolysis and condensation reaction, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space groupPbca with a = 8.3779（13）, b = 17.607（3）, c = 26.774（4） A, V= 3949.2（11） A3, Z=8, Dc = 1.448 g/cm3, μ = 0.117 mm-l, F（000） = 1776, the final R = 0.0553 and wR = 0.1516 for 2354 observed reflections with 1 〉 2σ（/）. X-ray diffraction analysis reveals that the title compound is almost coplanar except for the trifluoromethyl and phenyl moieties. In the crystal packing, the molecules are linked by intermolecular O（lW）-H（1WA）-＂N（2）, O（1W）-H（1WA）.--N（4） and N（5）-H（5A）...O（lW） hydrogen bonds via water molecules and stacked through π-π stacking interactions. The preliminary bioassay suggested that the title compound exhibits relatively good antitumor activity against HepG2 and BCG-823.

Syntheses, Crystal Structures and Hydrogen-bonding Motif of Two Glycoluril Derivatives

The synthesis and aggregation behavior of two glycoluril derivatives were descrybed.The crystal of compound 1 belongs to the triclinic system,space group P1,with a=8.946(1),b=13.445(2),c=20.361(3)?,α=89.517(3),β=84.405(3),γ=86.325(3)°,Z=2,V=2432.1(6)?3,Dc=1.293 g·cm-3,C48H34N6O6·2DMSO,Mr=947.07,F(000)=992,μ=0.170 mm-1,the final R=0.1606 and wR=0.2410 for 4382 observed reflections(Ⅰ>2σ(Ⅰ)).The crystal of compound 2belongs to the monoclinic system,space group P21/c,with a=9.500(3),b=24.522(8),c=17.997(6)A,Z=2,V=4054(2)A^3,Dc=1.296 g·cm^-3,C48H34N6O6,Mr=790.81,F(000)=1648,μ=0.087mm-1,the final R=0.2146 and wR=0.2535 for 2878 observed reflections(Ⅰ>2σ(Ⅰ)).Unlike the highly conserved R22(8)hydrogen-bonding amide···amide homosynthon,the structural analysis indicated that compound 1 selected the C(20)hydrogen-bonding motif and 2 selected the R22(34)hydrogen-bonding motif,which revealed the competition from remote solvent molecule and the interference of the molecular hydrocarbon core in crystal packing.The supramolecular structure revealed molecule 1 is further linked into a one-dimensional chain and 2 into a two-dimensional interwoven plane by N–H···N hydrogen bonds.

Theoretical Study on the Electronic Structures and Spectral Properties of 1,8-Naphthalimide Derivatives

The molecular geometries, frontier molecular orbital properties, and absorption and emission properties of three 4-phenoxy-1,8-naphthalimide derivatives, namely 4-phenoxy-N-（2-hydroxyethyl）-1,8-naphthalimide（1）,4-（2-tert-butylphenoxy）-N-（2-hydroxyethyl）-1,8-naphthalimide（2）, and 4-[2,4-di（tert-butyl）]phenoxy-N-（2-hydroxyethyl）-1,8-naphthalimide（3）, are investigated by density functional theory（DFT） and time-dependent density functional theory（TD-DFT） calculations in conjunction with polarizable continuum models（PCMs）. Four functionals and ten basis sets are employed for 1 to calculate the electron transition energies, which were compared with the experimental observations. Our results reveal that the B3LYP/6-311＋G（d,p） method is the best choice to reproduce the experimental spectra. Moreover, the effects of substituents on the molecular geometries, electronic structures, absorption and emission spectra are also studied at the B3LYP/6-311＋G（d,p） level. We find that the gap between the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO） decreases with increasing the number of tert-butyl substituents onto the phenoxy groups, suggesting red-shift of the absorption and emission bands. This is related to the increase of conjugation from 1 to 2 and 3. Our calculations are in good agreement with the experimental results.

Metabolome profiling of stratified seeds provides insight into the regulation of dormancy in Davidia involucrata

Dove tree(Davidia involucrata),a tertiary vestige species,is well-adapted to cool conditions.Dormancy in D.involucrata seed lasts for an extremely long period of time,typically between 3 and 4 years,and this characteristic makes the species an excellent model for studying the mechanisms of seed dormancy.The molecular mechanisms governing germination control in D.involucrata are still unknown.Seed stratification have been reported to enhance germination in recalcitrant seeds.We performed a widely targeted metabolome profiling to identify metabolites and associated pathways in D.involucrata seeds from six different moist sand stratification durations(0-30 months) using the ultra-high-performance liquid chromatography-Q Exactive Orbitrap-Mass spectrometry.There was an increasing germination rate with prolonged stratification durations(12-30 months).Furthermore,we detected 10,008 metabolites in the stratified seeds.We also detected 48 differentially accumulated metabolites(DAMs) between all stratification periods in the seeds,with 10 highly conserved metabolites.Most of the differentially accumulated metabolites between unstratified and stratified seeds were enriched in purine metabolism,pyrimidine metabolism,flavone and flavonol biosynthesis,phenylpropanoid biosynthesis,and arginine biosynthesis pathways.Key phytohormones,abscisic acid,indole-3 acetic acid,and sinapic acid were differentially accumulated in the seeds and are predicted to regulate dormancy in D.involucrata.We have provided extensive metabolic information useful for future works on dove tree germination study.

Facile synthesis and antitumor activity of novel 2-trifluoromethylthieno[2,3-d]pyrimidine derivatives

A series of novel 2-trifluoromethylthieno[2,3-d]pyrimidine derivatives were synthesized by a facile three-step procedure that afforded advantages of mild reaction conditions, simple protocol and good yields. The structures of the final compounds were confirmed by 1R, NMR, El-MS, elemental analysis, and X-ray diffraction. Preliminary bioassay results showed that some of the analogs exhibit excellent antitumor activity against MCF-7 and HepG2, especially compounds 3a, 3b, 3e and 3h exhibited higher activity than the positive control gefitinib.

A nanosilica/exfoliated graphene composite film-modified electrode for sensitive detection of methyl parathion

Graphene nanosheets （GS） were easily prepared through liquid-phase exfoliation of graphite powder in N,N-dimethylformamide （DMF） with the assistance of sodium citrate. Then, GS was coated onto a glassy carbon electrode （GCE） surface by drop to fabricate a GS]GCE nanointerface. Subsequently, by using tetraethylorthosilicate sol as precursor, nanosilica was electrochemically deposited onto the GS]GCE surface to produce a nanocomposite film electrode （nanosilicaJGSJGCE）. Electrochemical behaviors of methyl parathion （MP） on the nanosilica/GS/GCE surface were investigated thoroughly. It was found that the nanosilicaJGS nanocomposites can improve the redox peak currents of MP significantly due to the synergetic effect. The oxidation peak current was linearly related to MP concentration in the range from 0.0005 μmol/L to 5.6 μmol/L. The detection limit was calculated to be 0.07 nmol/L （SJN = 3）. The developed method was used to determine MP in real samples. The recoveries were in the range from 95.4% to 104.2%, demonstrating satisfactory results.