Abstract: [Object] Provided are a 11C-labeled acyclic retinoid that can be synthesized in a short time with a high yield and can be suitably used for PET for elucidating intracerebral kinetics, a PET probe using it, and methods for producing them. [Solution] The 11C-labeled acyclic retinoid of the present invention is characterized by being represented by the following chemical formula (a). This compound can be produced by a coupling step of cross-coupling a methyl iodide labelled with 11C and the following organotin compound (b) (provided that in the formula, R1 and R2 represent alkyl groups which may have a branch) in an aprotic solvent in the presence of a palladium complex, a phosphine ligand, and a cuprous halide.

Abstract: The present invention provides a method for introducing substituents into the ?-position and the ?-position of an ?,?-unsaturated ketone, which not only can be used for the synthesis of a prostaglandin by a three-component coupling process, but also enables synthesis of a prostaglandin in a high yield by one-pot operation without requiring the use of a large excess amount of any of the three components required for the synthesis or using a highly toxic heavy metal as a catalyst or a solvent that is highly toxic to living bodies, and a method for synthesizing a prostaglandin using the same technical means.

Abstract: An object of the invention is to provide an 11C-labeled catechol derivative having sufficient radioactivity to obtain an imaging image by a PET apparatus, a PET probe of a phosphorylated tau aggregation inhibitor using the same, and a method for producing them. The 11C-labeled catechol derivative of the present invention is represented by the following general formula (a) (wherein R is a substituent having an isopropylamino group, and the carbon at the 2-position of the isopropylamino group is labeled with 11C).

Abstract: The present invention provides a method for introducing substituents into the ?-position and the ?-position of an ?,?-unsaturated ketone, which not only can be used for the synthesis of a prostaglandin by a three-component coupling process, but also enables synthesis of a prostaglandin in a high yield by one-pot operation without requiring the use of a large excess amount of any of the three components required for the synthesis or using a highly toxic heavy metal as a catalyst or a solvent that is highly toxic to living bodies, and a method for synthesizing a prostaglandin using the same technical means.

Abstract: An object of the invention is to provide an 11C-labeled catechol derivative having sufficient radioactivity to obtain an imaging image by a PET apparatus, a PET probe of a phosphorylated tau aggregation inhibitor using the same, and a method for producing them. The 11C-labeled catechol derivative of the present invention is represented by the following general formula (a) (wherein R is a substituent having an isopropylamino group, and the carbon at the 2-position of the isopropylamino group is labeled with 11C).

Abstract: An object of the invention is to provide a 11C-labeled O6-benzylguanine capable of obtaining a PET image and a process for producing the same. The 11C-labeled O6-benzylguanine of the invention is represented by the following chemical formula (a). The 11C-labeled O6-benzylguanine is produced by: a coupling step of cross-coupling a methyl iodide labeled with 11C and the following organotin compound (b) (R1 represents an alkyl group, and R2 and R3 represent a leaving group which can be eliminated with a base) in the presence of a palladium complex, a phosphine ligand, and cuprous halide in an aprotic lactam; and a desorption step of desorbing the leaving groups R2 and R3 of the coupling product obtained by the coupling step with a base.

Abstract: An object of the invention is to provide a 11C-labeled O6-benzylguanine capable of obtaining a PET image and a process for producing the same. The 11C-labeled O6-benzylguanine of the invention is represented by the following chemical formula (a). The 11C-labeled O6-benzylguanine is produced by: a coupling step of cross-coupling a methyl iodide labeled with 11C and the following organotin compound (b) (R1 represents an alkyl group, and R2 and R3 represent a leaving group which can be eliminated with a base.) in the presence of a palladium complex, a phosphine ligand, and cuprous halide in an aprotic lactam; and a desorption step of desorbing the leaving groups R2 and R3 of the coupling product obtained by the coupling step with a base.

Abstract: Provided is a method whereby a heteroaromatic ring aryl can be very rapidly methylated at a high yield. In an N-alkyl-2-pyrrolidinone, a heteroaromatic ring aryltrialkylstannan is cross-coupled with methyl iodide in the presence of a palladium complex, a phosphine ligand, a cuprous halide, a carbonic acid salt and/or an alkali metal fluoride to thereby rapidly methylate the heteroaromatic ring aryl. (Formula shows a case wherein the heteroaromatic ring aryl is a pyridyl group.

Abstract: Viruses, and particularly RNA viruses, have high mutation rates. Hence, antiviral agents that have been developed to date targeting protease or reverse transcriptase of viruses have quickly lost their effectiveness and resistant viruses have emerged. Also, in recent years, viral diseases caused by various new viruses such as SARS, avian influenza, and the hepatitis C have become social menaces. Therefore, the development of a novel antiviral agent that can cope with a virus resistant to an existing drug or a new virus and has a wide range of applications has been demanded. The present invention provides a novel anti-RNA viral agent and a method for use thereof. The present invention further provides an anti-RNA viral agent that is also effective against a new virus or a drug-resistant virus, and a method for use thereof.

Abstract: Provided is a method whereby a heteroaromatic ring aryl can be very rapidly methylated at a high yield. In an N-alkyl-2-pyrrolidinone, a heteroaromatic ring aryltrialkylstannan is cross-coupled with methyl iodide in the presence of a palladium complex, a phosphine ligand, a cuprous halide, a carbonic acid salt and/or an alkali metal fluoride to thereby rapidly methylate the heteroaromatic ring aryl. (Formula shows a case wherein the heteroaromatic ring aryl is a pyridyl group.

Abstract: Viruses, and particularly RNA viruses, have high mutation rates. Hence, antiviral agents that have been developed to date targeting protease or reverse transcriptase of viruses have quickly lost their effectiveness and resistant viruses have emerged. Also, in recent years, viral diseases caused by various new viruses such as SARS, avian influenza, and the hepatitis C have become social menaces. Therefore, the development of a novel antiviral agent that can cope with a virus resistant to an existing drug or a new virus and has a wide range of applications has been demanded. The present invention provides a novel anti-RNA viral agent and a method for use thereof. The present invention further provides an anti-RNA viral agent that is also effective against a new virus or a drug-resistant virus, and a method for use thereof.