AgSbF-Mediated Selective Thiolation and Selenylation at C-4 Position of Isoquinolin-1(2 H)-ones.

A new and facile AgSbF-mediated protocol for the construction of C-4 thiolated or selenylated isoquinolin-1(2 H)-ones via a radical pathway was established. This reaction proceeded efficiently with excellent regioselectivity, a broad substrate scope, and good functional group tolerance. A radical reaction mechanism involving thiyl radicals as key intermediates is proposed for the present transformation.

Novel HPPD inhibitors: triketone 2H-benzo[b][1,4]oxazin-3(4H)-one analogs.

Background: Herbicides that inhibit 4-hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.

Route to Substituted Furan-2(5H)-ones from cyclo-Alkenecarboxylic Acids and Acrylates via C-H Activation.

Under rhodium(III) catalysis, four kinds of cycloalkenecarboxylic acids successfully reacted with acrylates via direct activation of the β-alkenyl C-H bond. The present protocol provides the facile and highly efficient synthesis of substituted furan-2(5H)-ones from readily available starting materials with moderate to good yields. In addition, their possible reaction mechanisms were also discussed.

Synthesis and herbicidal activities of novel 3-(substituted benzyloxy or phenoxy)-6-methyl-4-(3-trifluoromethylphenyl)pyridazine derivatives.

Background: 4-(3-Trifluoromethylphenyl)pyridazine represents a new series of compounds with bleaching and herbicidal activities.

Results: A total of 43 novel 3-(substituted benzyloxy or phenoxy)-6-methyl-4-(3-trifluoromethylphenyl)pyridazine derivatives were synthesised, and their bleaching and herbicidal activities were evaluated through Spirodela polyrrhiza and greenhouse tests. Some compounds exhibited excellent herbicidal activities, even at a dose of 7.

(Z)-3-[(4-Eth-oxy-phen-yl)(hy-droxy)methyl-idene]-1-isopropyl-pyrrolidine-2,4-dione.

In the title compound, C(16)H(19)NO(4), a potent new herbicide, the dihedral angle between the benzene and pyrrolidine rings is 11.09 (8)°. Intra-molecular O-H⋯O and C-H⋯O hydrogen bonds are observed.

1-sec-Butyl-3-[hy-droxy(1-methyl-1H-indol-3-yl)methyl-idene]pyrrolidine-2,4-dione.

In the title compound, C(18)H(20)N(2)O(3), the dihedral angle between the indole ring system (r.m.s.

4-[(Z)-Allyl-amino-(phen-yl)methyl-ene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.

The title compound, C(20)H(19)N(3)O, exists in a keto-enamine tautomeric form. The pyrazolone ring makes dihedral angles of 20.52 (10) and 77.

(4Z)-4-[(Cyclo-propyl-amino)(phen-yl)methyl-ene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.

In the title compound, C(20)H(19)N(3)O, the dihedral angles formed by the pyrazolone ring with the two phenyl rings are 64.27 (6) and 17.00 (6)°.

(4Z)-4-[(4-Methoxy-benzyl-amino)(phen-yl)methyl-ene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.

In the title compound, C(25)H(23)N(3)O(2), the dihedral angles formed by the pyrazolone ring with the three aromatic rings are 14.59 (7), 79.35 (5) and 87.

4-{(Z)-(sec-Butyl-amino)(phen-yl)methyl-ene}-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one.

In the title compound, C(21)H(23)N(3)O, the dihedral angles formed by the pyrazolone ring with two phenyl rings are 10.38 (8) and 76.94 (6)°.

Novel protoporphyrinogen oxidase inhibitors: 3H-pyrazolo[3,4-d][1,2,3]triazin-4-one derivatives.

A series of 3 H-pyrazolo[3,4-d][1,2,3]triazin-4-one derivatives were synthesized as candidate herbicides by diazotization of different 5(3)-amino- N-phenyl-1 H-pyrazole-4-carboxamide derivatives prepared by the reaction of substituted 5(3)-amino-pyrazole-4-carbonyl chloride with a substituted aniline. Their structures were identified by (1)H NMR and elemental analyses. The isomers D and E were isolated, and their structures were identified by two-dimensional NMR analyses (heteronuclear single quantum coherence and heteronuclear multiple-bond correlation) and single-crystal X-ray diffraction analysis.

Synthesis and herbicidal activities of novel 3-N-substituted amino-6-methyl-4-(3-trifluoromethylphenyl)pyridazine derivatives.

4-(3-Trifluoromethylphenyl)pyridazine is a new series of compounds with bleaching and herbicidal activities. Starting from ethyl 2-(3-trifluoromethylphenyl)acetate, an important intermediate 7 was synthesized in five steps with a moderate total yield of 51.5% in a safe and practical way.

Methyl 3-(4-{6-methyl-4-[3-(trifluoro-meth-yl)phen-yl]pyridazin-3-yl-oxy}phen-yl)propanoate.

In the title compound, C(22)H(19)F(3)N(2)O(3), the benzene rings of the trifluoro-methyl-phenyl and benzoyl-phenyl groups form dihedral angles of 41.89 (10) and 67.44 (10)°, respectively, with the pyridazine ring.

6-Methyl-2-p-tolyl-4-[3-(trifluoro-meth-yl)phen-yl]pyridazin-3(2H)-one.

In the title mol-ecule, C(19)H(15)F(3)N(2)O, the benzene rings of the tolyl and trifluoro-methyl-phenyl groups form dihedral angles of 64.1 (2) and 38.5 (2)°, respectively, with the pyridazine ring.

4-[3-(Trifluoro-meth-yl)phen-yl]-5,6,7,8-tetra-hydro-cinnolin-3(2H)-one.

The title compound, C(15)H(13)F(3)N(2)O, contains one benzene ring, one cyclo-hexane ring and a pyridazine ring. The dihedral angle formed by the pyridazine ring with the benzene ring is 61.5 (2)°.

The synthesis and herbicidal activity of 1-alkyl-3-(alpha-hydroxy-substituted benzylidene)pyrrolidine-2,4-diones.

In the search for better herbicides a series of 1-alkyl-3-(alpha-hydroxy-(un)substituted benzylidene)pyrrolidine-2,4-diones were prepared and their structure-activity relationships studied. All their structures have been confirmed by (1)H-NMR and elemental analysis. The preliminary bioassay results indicated that some of them have high herbicidal activity against annual dicotyledonous and monocotyledonous plants.

Design, synthesis, and quantitative structure-activity relationship study of herbicidal analogues of pyrazolo[5,1-d][1,2,3,5]tetrazin-4(3H)ones.

A series of pyrazolo[5,1-d][1,2,3,5]tetrazin-4(3H)one derivatives were designed, synthesized, and evaluated for their herbicidal activities where some of these compounds provided >80% control of Brassica campestris at 10 microg/mL. Quantitative structure-activity relationship studies were performed on these compounds using physicochemical parameters (electronic, Verloop, or hydrophobic) as independent parameters and herbicidal activity as a dependent parameter, where herbicidal activity correlated best (r > 0.8) with physicochemical parameters in this set of molecules.

3-[(Hydr-oxy)(4-isoprop-oxy-2-methoxy-phen-yl)methyl-ene]-1-isopropyl-pyrrol-idine-2,4-dione.

The title compound, C(18)H(23)NO(5), a potential herbicide, has an enol group that is intra-molecularly hydrogen bonded to a keto O atom. The dihedral angle between the six-membered ring formed by the enol group and the aromatic benzene ring is 53.35 (6)°.

tert-Butyl 4-({[(E)-1,3-dimethyl-5-phen-oxy-pyrazol-4-yl]meth-yl}amino-oxymeth-yl)benzoate.

The title compound, C(24)H(27)N(3)O(4), also known as fenpyroximate, is a commercial acaricide. The benzene ring of the phen-oxy group is approximately perpendicular to the pyrazole ring with a dihedral angle of 84.37 (11)°.

A quantitative structure-activity relationship study of herbicidal analogues of alpha-hydroxy-substituted 3-benzylidenepyrrolidene-2,4-diones.

A series of pyrrolidine-2,4-dione and piperidine-2,4-dione derivatives were prepared and evaluated for their herbicidal activities where some of these compounds exhibited good bioactivity against Echinochloa crus-galli in comparison with sulcotrione. Quantitative structure-activity relationship studies were performed on these compounds using physicochemical parameters (hydrophobic, electronic, and Taft) as independent parameters and herbicidal activity as a dependent parameter, where herbicidal activity correlated best (r > 0.8) with hydrophobic (pi(o) + pi(p)), steric (Es), STERIMOL (B4), indicator (H(M)), van der Waals volume (V), and electronic parameter (sigma(m) + sigma(p)) in this set of molecules; the optimum van der Waals volume for R(2) is about 41.

Synthesis and herbicidal activity of novel alpha,alpha,alpha-trifluoro-m-tolyl pyridazinone derivatives.

A series of novel alpha,alpha,alpha-trifluoro-m-tolyl pyridazinone derivatives was synthesised. Herbicidal activities of the two intermediate compounds and 15 pyridazinone derivatives were evaluated through barnyardgrass and rape cup tests and Spirodela polyrrhiza (L.) Schleiden tests.

Ethyl 5-amino-3-(4,6-dimethylpyrimidin-2-ylamino)-1-methyl-1H-pyrazole-4-carboxylate and ethyl 5-amino-3-(4,6-dimethylpyrimidin-2-ylamino)-1-(2-nitrophenylsulfonyl)-1H-pyrazole-4-carboxylate.

The molecular structures of ethyl 5-amino-3-(4,6-dimethylpyrimidin-2-ylamino)-1-methyl-1H-pyrazole-4-carboxylate, C13H18N6O2, (I), and ethyl 5-amino-3-(4,6-dimethylpyrimidin-2-ylamino)-1-(2-nitrophenylsulfonyl)-1H-pyrazole-4-carboxylate, C18H19N7O6S, (II), have been determined. There are two intramolecular N-H..

Antibiotic prophylaxia in patients with severe acute pancreatitis.

Background: The prophylactic use of antibiotics in patients with severe acute pancreatitis remains contentious. This study was undertaken to review the current studies on antibiotic prophylaxis in patients with severe acute pancreatitis.

Data Resources: All papers found by a Medline search were relevant to human trials of antibiotic prophylaxis in patients with severe acute pancreatitis.