Liang-Nian He

A FACILE SYNTHESIS OF DERIVATIVES OF 4-ARYL-1,3,2-DIOXAPHOSPHORINANE-2-SULFIDE VIA LAWESSON'S REAGENT

Abstract The derivatives of 4-aryl-1,3,2-dioxaphosphorinane-2-sulfide, namely, 4-aryl-5,5-dimethyl-1,3,2-dioxaphosphorinane-2-sulfides (6) were synthesized in moderate yields by the cyclization reaction of 1-aryl-2,2-dimethyl-1,3-propanediols(5) with Lawessons reagent using acetonitrile as a solvent. 8-Membered cyclic trithiopyrophosphonates (7) were isolated as side-products.

A novel route to spiro phosphorus-heterocycle via Lawesson's reagent

ABSTRACT 2-Aryl-spiro-[5,5]-1,3,2-dioxaphosphorinane-2-sufides were prepared by the cyclization reaction of Lawessons reagent with pentaerythritol and monobenzalpentaerythritol, respectively.

Application of Lawesson'S Reagent in Syntheses of Biologically Active Phosphorus Heterocycles

Abstract The reactions of Lawessons reagent-2.4-Bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide, with long-chain 1 - glycerin rnonoethers, 3-mercapto-4-amino-1,2,4-triazoles, 1,3-disubstituents glycinamides, and 2-methyl-1,3-butadiene have been investigated and found to form cyclic analogues 1, fused heterocycles 2, 5-membered phosphorus rings 3, and 6-membered heterocycle 4, respectively, in moderate yield. The preliminary biological screening tests for these rings showed that they possess significant selective herbicidal activity against rape.

A FACILE SYTNHESIS OF 1-ALKYL-1,3,2-DIAZAPHOSPHOLIDIN-4-THlONE-2-SULFiDE VIA LAWESSON'S REAGENT

2,4-Bis(4-methoxyphenyl)-l,3,2,4-dithiadiphosphetane-2,4-disulfide(Lawessons Reagent), was refluxed with 3-alkyl glycinamides 1 in anhydrous toluene to yield l-alkyl-l,3,2-diazaphospholidin-4-thione-2-sulfides_2 . The structure was confirmed by elementary analysis, NMR, ER, MS. The results of preliminary bioassay indicated that some of the title compounds possess seletive herbicidal activity.

A Facile Synthesis of Fused Phosphorus-Heterocycle with Bioactivity via Lawesson's Reagent

A convenient one-pot synthesis of fused phosphorus-heterocycles with biological activity via the cyclization reactions of Lawessons reagent with bifunctional substrates is reported.

Synthesis and insecticidal activity of O-aryl O-(1,2,2,2-tetrachloroethyl)phosphoramidothioates and their thiophosphoric hydrazides [1]

O-Aryl O-(1,2,2,2-tetrachoroethyl)phos- phoramidothioates 3a–h and their thiophosphoric hydrazides 4a–e were synthesized by reactions of O-aryl O-(1,2,2,2-tetrachoroethyl)thiophosphorochloridates 2 with amines and hydrazines, respectively. Their structures were characterized by elemental analysis IR 1H NMR, 31P NMR, and MS. The O-aryl O-(1,2,2,2-tetrachloroethyl)thiophosphoric hydrazides 4a–d (R2=H) can be transformed into 1,3,4,2-oxadiazaphospholanes 5a–d by the reaction of triethylamine. The results of preliminary bioassays indicated that some of the title compounds have good insecticidal activities against nematodes (Meloidogyne spp.) and pea aphids.

A CONVENIENT SYNTHESIS OF DERIVATIVES OF 1,3,2- DIOXAPHOSPHOCANE-2-SULFIDE WITH BIOACITIVITY VIA LAWESSON'S REAGENT

Lawessons reagent, 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disufide, reacted with the substituted 1,5-bisphenol 1 to afford derivatives of l,3,2-dioxaphosphocane-2-sulfide 2, which were found to possess selective herbicidal activity against rape.

SYNTHESIS OF 1,3-DIARYL-1,3,2-DIAZAPHOSPHOLIDIN-4-THIONE-2-SULFIDES VIA LAWESSON'S REAGENT

Abstract 2,4-Bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulfide (Lawessons Reagent, LR), was treated with N,N′-diaryl glycinamides (1) in anhydrous toluene as a solvent at 100°C to form 1,3-diaryl-1,3,2-ciazaphospholidin-4-thione-2-sulfides (2) Compatible analytical and spectroscopic data were obtained for all the new compounds. A mechanism was proposed to explain the formation of compound 2f. The biological activity of the title products was also tested and some of them showed good herbicidal activity.

SYNTHESIS OF NEW ß-(1,3-BENZOTHIAZOLE-2-)PHOSPHORIC HYDRAZIDES

Abstract β-(1,3-Benzothiazole-2-)phosphoric hydrazides 2 were synthesized by Atherton-Tod method using potassium carbonate as a base in the presence of tetrabutylammonium bromide as a phase transfer catalyst or by the intermolecular condensation of the hydrazines 1 with phosphorochloridate, (R3O)(R4O)P(O)Cl, in the presence of a base, triethylamine. Thermal decomposition at 180°C of 2a caused the intramolecular shift of ethyl group from oxygen to β -nitrogen atom, and formed the monoester phosphoric hdrazide 3, whose structure was determined by elementary analysis, IR, 1H NMR, 13C NMR, 31P NMR, MS spectra. The biological activity of the title product was also tested and some of them showed good fungicidal activity.

The Quantitative Structure-Herbicidal Activity Relationship of 1-Alkyl-1,3,2-Diazaphospholidin-4-Thione-2-Sulfides

A number of 1-alkyl-1,3,2-diazaphospholidin-4-thione-2-sulfides(2) have been synthesized by the cyclization reaction of Lawessons reagent with 3- alkyl- glycinamides(1). The bio-assay indicates that some of compounds prepared have good selective herbicidal activity and the quantitative structure- herbicidal activity relationship (QSAR) of compounds(2) has also been studied.