Ajinomoto Co., Ltd.

Takayoshi Torii

Kunisuke Izawa

Daisuke Takahashi

Satoshi Katayama

Tomoyuki Onishi

Kunihiro Hirai

Ryotaro Nakaya

Doo Ok Jang

Dae Hyan Cho

Takashi Nakano

Ryoji Noyori

Masakazu Nakazawa

Takao Ikariya

Toyoto Hijiya

Naoko Hirose

Takayuki Hamada

Yoshihito Koguchi

Morpholino oligonucleotides can be produced efficiently in a high yield by a liquid-phase synthesis method, which includes subjecting a reaction mixture of a condensation reaction to an extraction operation and separating the morpholino oligonucleotide as a resultant product to the organic layer side.

Morpholino oligonucleotide manufacturing method

Using a morpholino nucleotide wherein 5'-hydroxy group or a hydroxy group present on the substituent of the 5&#x2032;-hydroxy group is protected by a protecting group having an alkyl group having not less than 10 and not more than 300 carbon atoms and/or an alkenyl group having not less than 10 and not more than 300 carbon atoms as a starting material, a method capable of efficiently producing the morpholino oligonucleotide in a high yield by a liquid phase synthesis can be provided.

The present invention provides a protected nucleotide for elongation, which can be purified efficiently and in a high yield by a liquid-liquid extraction operation, and can achieve an oligonucleotide production method by a phosphoramidite method. It has been found that the above-mentioned problem can be solved by a particular oligonucleotide comprising a protected base and/or particular oligonucleotide protected by a branched chain-containing aromatic group at 3'-position.

Oligonucleotide with protected base

The present invention provides a method for producing an inosine derivative represented by the following general formula (1) including the steps of subjecting an inosine derivative of general formula (3) to dithiocarbonylation and carrying out radical reduction of the obtained compound. According to the present invention there can be produced compounds useful as anti-AIDS drugs on industrial scale. wherein R1 may be the same or different and are each benzyl group, benzhydryl group or trityl group, each of which may have a substituent in general formulas (1) and (3).

Inosine derivatives and production methods therefor

A process of preparing an optically active halohydrin compound characterized by comprising asymmetric hydrogen transfer reduction of an &#x3b1;-haloketone compound in the presence of a group 9 transition metal compound having a substituted or unsubstituted cyclopentadienyl group and an optically active diamine compound. The asymmetric hydrogen transfer reduction is preferably conducted in the presence of a base.

Process for producing optically active halohydrin compound

The present invention provides a method for efficiently producing &bgr;-D-ribofuranose derivatives or optical isomers thereof, useful as synthetic intermediates of pharmaceutical nucleic acid-series products. The method comprises a step of producing 1-O-benzyl-&bgr;-D-ribofuranose-2,3,5-triacetate or an optical isomer thereof by allowing &bgr;-D-ribofuranose-1,2,3,5-tetraacetate or an optical isomer thereof to react with a benzyl alcohol in the presence of acid catalysts and a step of hydrolyzing the resulting 1-O-benzyl-&bgr;-D-ribofuranose-2,3,5-triacetate in the presence of a base to produce 1-O-benzyl-&bgr;-D-ribofuranose or an optical isomer thereof.

Method for producing &bgr;-D-ribofuranose derivatives or optical isomers thereof

An N-9-position alkylated form is selectively precipitated by subjecting a mixture containing the N-9-position alkylated form and an N-7-position alkylated form of 2-amino-6-halopurine to a crystallization step using a mixed solvent of an organic solvent and water. Then, this N-9-position alkylated form is reduced to give famciclovir. By this method of the present invention, famciclovir known as an antiviral agent, and an intermediate compound therefor can be efficiently produced.

Production method of famciclovir and production and crystallization method of intermediate therefor

A process for producing &agr;-amino-dihalogenated methyl ketone derivatives by reacting an N-protected &agr;-amino acid ester with a dihalomethyl lithium is provided. This process is suitable for the production on an industrial scale and by this process, &agr;-amino-dihalogenated methyl ketone derivatives and &bgr;-amino-&agr;-hydroxycarboxylic acid derivatives can be obtained efficiently and economically advantageously.

Growing community of inventors

Kawasaki, Japan

Takayoshi Torii