The present invention provides a novel dihydroorotic acid dehydrogenase inhibitor which is applicable to various diseases. When used as an active ingredient, a compound represented by formula (I): ##STR00001##
(wherein X represents a halogen atom, R.sup.1 represents a hydrogen atom, R.sup.2 represents an alkyl group containing 1 to 7 carbon atoms, R.sup.3 represents —CHO, and R.sup.4 represents —CH.sub.2—CH═C(CH.sub.3)—R.sup.0 (wherein R.sup.0 represents an alkyl group containing 1 to 12 carbon atoms which may have a substituent on the terminal carbon and/or on a non-terminal carbon, etc.)),
an optical isomer thereof or a pharmaceutically acceptable salt thereof has a high inhibitory effect on dihydroorotic acid dehydrogenase and can be used as an immunosuppressive agent, a therapeutic agent for rheumatism, an anticancer agent, a therapeutic agent for graft rejection, an antiviral agent, an anti-H. pylori agent, a therapeutic agent for diabetes or the like.

The present invention provides a novel dihydroorotic acid dehydrogenase inhibitor which is applicable to various diseases. When used as an active ingredient, a compound represented by formula (I): ##STR00001##
(wherein X represents a halogen atom, R.sup.1 represents a hydrogen atom, R.sup.2 represents an alkyl group containing 1 to 7 carbon atoms, R.sup.3 represents —CHO, and R.sup.4 represents —CH.sub.2—CH═C(CH.sub.3)—R.sup.0 (wherein R.sup.0 represents an alkyl group containing 1 to 12 carbon atoms which may have a substituent on the terminal carbon and/or on a non-terminal carbon, etc.)),
an optical isomer thereof or a pharmaceutically acceptable salt thereof has a high inhibitory effect on dihydroorotic acid dehydrogenase and can be used as an immunosuppressive agent, a therapeutic agent for rheumatism, an anticancer agent, a therapeutic agent for graft rejection, an antiviral agent, an anti-H. pylori agent, a therapeutic agent for diabetes or the like.

Provided are a complex prepared from ammonium salt-containing ligands and having such an equilibrium structural formula that the metal center takes a negative charge of 2 or higher, and a method for preparing polycarbonate via copolymerization of an epoxide compound and carbon dioxide using the complex as a catalyst. When the complex is used as a catalyst for copolymerizing an epoxide compound and carbon dioxide, it shows high activity and high selectivity and provides high-molecular weight polycarbonate, and thus easily applicable to commercial processes. In addition, after forming polycarbonate via carbon dioxide/epoxide copolymerization using the complex as a catalyst, the catalyst may be separately recovered from the copolymer.

Provided are a complex prepared from ammonium salt-containing ligands and having such an equilibrium structural formula that the metal center takes a negative charge of 2 or higher, and a method for preparing polycarbonate via copolymerization of an epoxide compound and carbon dioxide using the complex as a catalyst. When the complex is used as a catalyst for copolymerizing an epoxide compound and carbon dioxide, it shows high activity and high selectivity and provides high-molecular weight polycarbonate, and thus easily applicable to commercial processes. In addition, after forming polycarbonate via carbon dioxide/epoxide copolymerization using the complex as a catalyst, the catalyst may be separately recovered from the copolymer.

The invention provides a method for depolymerising a phenolic polymer, the method comprising reacting the phenolic polymer with dimethylsulphoxide (DMSO) and a hydrogen halide. The phenolic polymer may be selected from the group consisting of lignin and derivatives thereof. The hydrogen halide may be HBr. The quantity of hydrogen halide per gram of phenolic polymer may be from 30 mmoles to 70 mmoles. The quantity of DMSO per gram of phenolic polymer may be from 0.1 mole to 1 mole. The reaction may be performed at a temperature of from 100 to 120° C. The reaction may be carried out for between 10 h and 14 h. The product of the reaction may comprise vanillin.

The invention provides a method for depolymerising a phenolic polymer, the method comprising reacting the phenolic polymer with dimethylsulphoxide (DMSO) and a hydrogen halide. The phenolic polymer may be selected from the group consisting of lignin and derivatives thereof. The hydrogen halide may be HBr. The quantity of hydrogen halide per gram of phenolic polymer may be from 30 mmoles to 70 mmoles. The quantity of DMSO per gram of phenolic polymer may be from 0.1 mole to 1 mole. The reaction may be performed at a temperature of from 100 to 120° C. The reaction may be carried out for between 10 h and 14 h. The product of the reaction may comprise vanillin.

Disclosed herein are processes for synthesizing 2-hydroxy-6-((2-(1-isopropyl-1H-pyrazol-5-yl)-pyridin-3-yl)methoxy)benzaldehyde (also referred to herein as Compound (I)) and intermediates used in such processes. Compound (I) binds to hemoglobin and increases its oxygen affinity and hence can be useful for the treatment of diseases such as sickle cell disease.

Disclosed herein are processes for synthesizing 2-hydroxy-6-((2-(1-isopropyl-1H-pyrazol-5-yl)-pyridin-3-yl)methoxy)benzaldehyde (also referred to herein as Compound (I)) and intermediates used in such processes. Compound (I) binds to hemoglobin and increases its oxygen affinity and hence can be useful for the treatment of diseases such as sickle cell disease.

The present disclosure provides regioselective methods for synthesizing intermediates useful in making prostacyclin. The methods include heating the compound of Formula 2 at a temperature of 180° C. to 185° C. Wherein the heating ##STR00001##
comprises irradiating the compound of formula 2 with microwave radiation.

The present disclosure provides regioselective methods for synthesizing intermediates useful in making prostacyclin. The methods include heating the compound of Formula 2 at a temperature of 180° C. to 185° C. Wherein the heating ##STR00001##
comprises irradiating the compound of formula 2 with microwave radiation.