A method for producing butadiene, the method including: a first synthesis step of bringing a mixed gas containing hydrogen and carbon monoxide into contact with a first catalyst to obtain a primary product containing ethanol as an intermediate; and a second synthesis step of bringing the primary product into contact with a second catalyst to obtain butadiene.

A method for producing butadiene, the method including: a first synthesis step of bringing a mixed gas containing hydrogen and carbon monoxide into contact with a first catalyst to obtain a primary product containing ethanol as an intermediate; and a second synthesis step of bringing the primary product into contact with a second catalyst to obtain butadiene.

A method for producing butadiene, the method including: a first synthesis step of bringing a mixed gas containing hydrogen and carbon monoxide into contact with a first catalyst to obtain a primary product containing ethanol as an intermediate; and a second synthesis step of bringing the primary product into contact with a second catalyst to obtain butadiene.

The present invention relates to a new chemical synthesis, intermediates and catalysts useful for the preparation of the neprilysin (NEP) inhibitor sacubitril, inter alia via nitro 5 compounds. It further relates to new intermediate compounds and their use for said new chemical synthesis route, as well as a new catalyst ligand.

The present invention relates to a new chemical synthesis, intermediates and catalysts useful for the preparation of the neprilysin (NEP) inhibitor sacubitril, inter alia via nitro 5 compounds. It further relates to new intermediate compounds and their use for said new chemical synthesis route, as well as a new catalyst ligand.

An object of the present invention is to provide a method for producing m-dialkylbenzaldehyde by using a reaction starting material containing 1,4-dialkylbenzene. The method for producing m-dialkylbenzaldehyde represented by formula (3), comprising a step of allowing carbon monoxide to react on a reaction starting material containing 1,4-dialkylbenzene represented by formula (1) in the presence of a Bronsted acid and a Lewis acid, wherein the reaction starting material is 1,4-dialkylbenzene represented by formula (1), or a mixture of 1,4-dialkylbenzene represented by formula (1) and 1,3-dialkylbenzene represented by formula (2), containing 10 mol % or more of the 1,4-dialkylbenzene represented by formula (1), wherein in formulae (1) to (3), R.sup.1 represents a methyl group or an ethyl group, and R.sup.2 represents a chain or cyclic alkyl group having 3 or more and 6 or less carbon atoms that has a tertiary carbon at the benzyl position. ##STR00001##

In a cross coupling reaction, in a case where a halogen atom is selected as the leaving group of the raw material compound, a harmful halogen waste forms as a by-product after the reaction, and disposal of the waste liquid is complicated and environmental burden is high. In a carbon-hydrogen activation cross coupling reaction which requires no halogen atom as the leaving group, although no halogen waste forms as a by-product, the reaction substrate is considerably restricted, and the reaction remains a limited molecular construction method. A method for producing an aromatic compound, which comprises subjecting an aromatic nitro compound and a boronic acid compound to a cross coupling reaction in the presence of a metal catalyst.

In a cross coupling reaction, in a case where a halogen atom is selected as the leaving group of the raw material compound, a harmful halogen waste forms as a by-product after the reaction, and disposal of the waste liquid is complicated and environmental burden is high. In a carbon-hydrogen activation cross coupling reaction which requires no halogen atom as the leaving group, although no halogen waste forms as a by-product, the reaction substrate is considerably restricted, and the reaction remains a limited molecular construction method. A method for producing an aromatic compound, which comprises subjecting an aromatic nitro compound and a boronic acid compound to a cross coupling reaction in the presence of a metal catalyst.

In a cross coupling reaction, in a case where a halogen atom is selected as the leaving group of the raw material compound, a harmful halogen waste forms as a by-product after the reaction, and disposal of the waste liquid is complicated and environmental burden is high. In a carbon-hydrogen activation cross coupling reaction which requires no halogen atom as the leaving group, although no halogen waste forms as a by-product, the reaction substrate is considerably restricted, and the reaction remains a limited molecular construction method. A method for producing an aromatic compound, which comprises subjecting an aromatic nitro compound and a boronic acid compound to a cross coupling reaction in the presence of a metal catalyst.

The regio-selective functionalization of a dialkyl benzene compound

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wherein the ratio of the compound functionalized at position (a) to the compound functionalized at the position (b) is at least 70:30, more particularly at least 80:20, still more particularly at least 85:15, and still more particularly at least 90:10, characterised in that the substituent R is an isobutyl group.