An object of the present invention is to provide a method for producing 2,4-dialkylbenzaldehyde with excellent conversion rate and yield, and excellent regioselectivity for formylation, by allowing carbon monoxide to react on a starting material containing a specific m-dialkylbenzene in the presence of hydrogen fluoride and boron trifluoride. The method for producing 2,4-dialkylbenzaldehyde according to the present invention comprises a step of allowing carbon monoxide to react on a starting material containing m-dialkylbenzene represented by formula (1) in the presence of hydrogen fluoride and boron trifluoride for formylation at least at a position (a), wherein the starting material is a dialkylbenzene containing more than 90 mol % of m-dialkylbenzene represented by formula (1), and the number of moles of boron trifluoride relative to 1 mole of m-dialkylbenzene represented by formula (1) is 0.7 mol or more and 3.0 mol or less: ##STR00001## a wherein R.sup.1 represents an alkyl group having 1 or more and 3 or less carbon atoms, and R.sup.2represents a chain or cyclic alkyl group having 2 or more and 7 or less carbon atoms, with a secondary or tertiary carbon at the benzylic position, provided that the number of carbons of R.sup.2 is larger than the number of carbons of R.sup.1.

An object of the present invention is to provide a method for producing 2,4-dialkylbenzaldehyde with excellent conversion rate and yield, and excellent regioselectivity for formylation, by allowing carbon monoxide to react on a starting material containing a specific m-dialkylbenzene in the presence of hydrogen fluoride and boron trifluoride. The method for producing 2,4-dialkylbenzaldehyde according to the present invention comprises a step of allowing carbon monoxide to react on a starting material containing m-dialkylbenzene represented by formula (1) in the presence of hydrogen fluoride and boron trifluoride for formylation at least at a position (a), wherein the starting material is a dialkylbenzene containing more than 90 mol % of m-dialkylbenzene represented by formula (1), and the number of moles of boron trifluoride relative to 1 mole of m-dialkylbenzene represented by formula (1) is 0.7 mol or more and 3.0 mol or less: ##STR00001## a wherein R.sup.1 represents an alkyl group having 1 or more and 3 or less carbon atoms, and R.sup.2represents a chain or cyclic alkyl group having 2 or more and 7 or less carbon atoms, with a secondary or tertiary carbon at the benzylic position, provided that the number of carbons of R.sup.2 is larger than the number of carbons of R.sup.1.

A compound is provided of Formula (I)

##STR00001##

wherein R.sup.1 represents a C.sub.3 to C.sub.20 hydrocarbon group derived from an alcohol of formula R.sup.1OH, from a formate of formula R.sup.1OCHO, or a cinnamyl aldehyde of Formula (II)

##STR00002##

wherein a compound of Formula I is capable of releasing a compound, when oxidized, selected from the group consisting of a fragrant alcohol of formula R.sup.1OH, a fragrant formate ester of formula R.sup.1OCHO and aryl aldehyde of Formula (III)

##STR00003##

wherein R.sup.2 is, independently, hydrogen atom, hydroxyl group, optionally substituted C.sub.1-C.sub.6 alkyl group, C.sub.1-C.sub.6 alkoxy group, or O(CO)CH(CH3).sub.2 wherein any two of R.sup.2 may form an optionally substituted 5 or 6 membered ring. The compounds are useful for example as a precursor for the prolonged delivery or release of fragrant compounds such as fragrant alcohols, fragrant aldehydes or fragrant formates.

A compound is provided of Formula (I)

##STR00001##

wherein R.sup.1 represents a C.sub.3 to C.sub.20 hydrocarbon group derived from an alcohol of formula R.sup.1OH, from a formate of formula R.sup.1OCHO, or a cinnamyl aldehyde of Formula (II)

##STR00002##

wherein a compound of Formula I is capable of releasing a compound, when oxidized, selected from the group consisting of a fragrant alcohol of formula R.sup.1OH, a fragrant formate ester of formula R.sup.1OCHO and aryl aldehyde of Formula (III)

##STR00003##

wherein R.sup.2 is, independently, hydrogen atom, hydroxyl group, optionally substituted C.sub.1-C.sub.6 alkyl group, C.sub.1-C.sub.6 alkoxy group, or O(CO)CH(CH3).sub.2 wherein any two of R.sup.2 may form an optionally substituted 5 or 6 membered ring. The compounds are useful for example as a precursor for the prolonged delivery or release of fragrant compounds such as fragrant alcohols, fragrant aldehydes or fragrant formates.

Disclosed herein are embodiments of a method and system for converting ethanol to para-xylene. The method also provides a pathway to produce terephthalic acid from biomass-based feedstocks. In some embodiments, the disclosed method produces p-xylene with high selectivity over other aromatics typically produced in the conversion of ethanol to xylenes, such as m-xylene, ethyl benzene, benzene, toluene, and the like. And, in some embodiments, the method facilitates the ability to use ortho/para mixtures of methylbenzyaldehyde for preparing ortho/para xylene product mixtures that are amendable to fractionation to separate the para- and ortho-xylene products thereby providing a pure feedstock of para-xylene that can be used to form terephthalic anhydride and a pure feedstock of ortho-xylene that can be used for other purposes, such as phthalic anhydride.

Disclosed herein are embodiments of a method and system for converting ethanol to para-xylene. The method also provides a pathway to produce terephthalic acid from biomass-based feedstocks. In some embodiments, the disclosed method produces p-xylene with high selectivity over other aromatics typically produced in the conversion of ethanol to xylenes, such as m-xylene, ethyl benzene, benzene, toluene, and the like. And, in some embodiments, the method facilitates the ability to use ortho/para mixtures of methylbenzyaldehyde for preparing ortho/para xylene product mixtures that are amendable to fractionation to separate the para- and ortho-xylene products thereby providing a pure feedstock of para-xylene that can be used to form terephthalic anhydride and a pure feedstock of ortho-xylene that can be used for other purposes, such as phthalic anhydride.

The present invention is a process for preparing a 4-alkylbenzaldehyde (para-alkylbenzaldehyde). An alkylbenzene, solvated in a solvent comprising at least one aliphatic solvent having in the range of 3 to 15 carbons, is reacted with carbon monoxide, in the presence of an aluminum halide and a hydrogen halide acid. Disproportionation is reduced and proportion of para-alkyl-benzaldehyde is increased with respect to other methods.

The present invention is a process for preparing a 4-alkylbenzaldehyde (para-alkylbenzaldehyde). An alkylbenzene, solvated in a solvent comprising at least one aliphatic solvent having in the range of 3 to 15 carbons, is reacted with carbon monoxide, in the presence of an aluminum halide and a hydrogen halide acid. Disproportionation is reduced and proportion of para-alkyl-benzaldehyde is increased with respect to other methods.

Described are methods for preparing a deuterated aldehyde using N-heterocyclic carbene catalysts in a solvent comprising D.sub.2O. The methods may be used to convert a wide variety of aldehydes (e.g., aryl, alkyl, or alkenyl aldehydes) to C-1 deuterated aldehydes under mild reaction conditions without functionality manipulation.

Described are methods for preparing a deuterated aldehyde using N-heterocyclic carbene catalysts in a solvent comprising D.sub.2O. The methods may be used to convert a wide variety of aldehydes (e.g., aryl, alkyl, or alkenyl aldehydes) to C-1 deuterated aldehydes under mild reaction conditions without functionality manipulation.