An object is to provide a novel organophosphorus compound which can impart flame retardancy to an amorphous resin in a smaller addition amount without deteriorating heat resistance and transparency, and also can be applied to a wide range of resins, a flame retardant containing the same, and a method for producing an organophosphorus compound. An organophosphorus compound represented by the following general formula (1) (wherein R.sup.1 and R.sup.2 are independently hydrogen, an alkyl group having 1 to 15 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 15 carbon atoms, or an alkylaryl group having 7 to 15 carbon atoms, R.sup.3 and R.sup.4 are independently an alkyl group having 1 to 15 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 15 carbon atoms, an alkylaryl group having 7 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an aralkyloxy group having 7 to 15 carbon atoms, or an alkylaryloxy group having 7 to 15 carbon atoms, provided that R.sup.3 and R.sup.4 may be bound to each other to form a ring, and m and n are independently 1, 2, 3 or 4), a flame retardant containing the same, and a method for producing an organophosphorus compound.

The present invention provides novel cyclic phosphorus-containing compounds, namely hydroxyl-functional phospholene-1-oxides, serving as highly efficient reactive flame retardants in urethane systems, particularly in flexible polyurethane foams, semi-rigid and rigid polyurethane and polyisocyanurate foams. The invention further provides fire-retarded polyurethane compositions comprising said hydroxyl-functional phospholene-1-oxides.

The present invention provides novel cyclic phosphorus-containing compounds, namely hydroxyl-functional phospholene-1-oxides, serving as highly efficient reactive flame retardants in urethane systems, particularly in flexible polyurethane foams, rigid polyurethane foams and rigid polyisocyanurate foams. The invention further provides fire-retarded polyurethane compositions comprising said hydroxyl-functional phospholene-1-oxides.

A Formula of a phosphorous fire-retardant hardener having fire-retardant and heat-resistant properties as well as a low-dielectric constant. With a preparation of glass-fiber laminated board, the hardener meets UL-94V fire-retardant requirements and has a dielectric constant 5 of 4.0 (1 GHz).

Provided are an intrinsic flame-retardant resin with a low polarity, and a preparation method therefor and the use thereof. The intrinsic flame-retardant resin with a low polarity has a structure as shown in formula I and is a phenolic compound or resin which is prepared by a three-step reaction of allyl etherification, rearrangement and terminating with a phosphorus-containing group. The resin does not contain polar hydroxyl groups in the molecular formula thereof, and has a stable molecular structure, low polarity and high reactivity, and does not generate polar hydroxyl groups during application and processing, thereby avoiding the influence of secondary hydroxyl groups on the performance of products thereof. While the resin improves the dielectric performance, same still has crosslinkable groups which lead to no significant change in high temperature resistance after curing. Introduction of the phosphorus-containing capping group allows the resin to have intrinsic flame-retardant performance. Using the resin in the preparation of a metal foil clad laminate facilitates reducing the dielectric constant and dielectric loss of the metal foil clad laminate, and results in higher high temperature resistance and improved flame retardancy, so that the metal foil clad laminate has a good comprehensive performance and broad application prospects.

A phosphorus-containing compound, a phosphorus-containing flame retardant, and a preparation method thereof are provided. Also provided is a resin composition which comprises the phosphorus-containing flame retardant and an unsaturated bond-containing resin. The resin composition may be used to make various articles, such as a prepreg, a resin film, a resin-coated copper, a laminate or a printed circuit board, and achieves improvement in at least one, more or all properties including resin filling property of prepreg, flame retardancy, alkali resistance, glass transition temperature, thermal dimensional stability (ratio of dimensional change under heat), thermal resistance after moisture absorption, peeling strength, dielectric constant and dissipation factor.

This invention features compounds that modulate the activity of liver X receptors, pharmaceutical compositions including the compounds of the invention, and methods of utilizing those compositions for modulating the activity of liver X receptors in the treatment of cancer.

The present invention relates to a novel crystalline polymorphic form of 3-Hydroxy-4,5-bis-benzyloxy-6-benzyloxymethyl-2-phenyl-2-oxo-25-[1,2]oxaphosphinane and a method for preparing the same.

The invention features compounds of the general formula (I) in which the variable groups are as defined herein, and to their preparation and use.

##STR00001##

Disclosed embodiments concern a phosphorus-containing heterocyclic compound according to the formula ##STR00001##
One exemplary compound is ##STR00002##
Certain embodiments fluoresce with excitation by light. The compounds are useful as fluorescent probes and as bioisosteres. In some embodiments, the compounds are bioisosteres of alpha-quinolones. Also disclosed is a method for making the compounds.