The invention relates to a process for preparing a compound of (III) ##STR00001## wherein X is a leaving group; and R.sup.1 is C.sub.1-C.sub.6 alkyl;
which comprises oxidative rearrangement of a compound of formula (II) or a solvate thereof ##STR00002## Compounds of formula (III) are key intermediates in the synthesis of Bilastine.

The invention relates to a process for preparing a compound of (III) ##STR00001## wherein X is a leaving group; and R.sup.1 is C.sub.1-C.sub.6 alkyl;
which comprises oxidative rearrangement of a compound of formula (II) or a solvate thereof ##STR00002## Compounds of formula (III) are key intermediates in the synthesis of Bilastine.

The invention relates to a process for preparing a compound of (III) ##STR00001## wherein X is a leaving group; and R.sup.1 is C.sub.1-C.sub.6 alkyl;
which comprises oxidative rearrangement of a compound of formula (II) or a solvate thereof ##STR00002## Compounds of formula (III) are key intermediates in the synthesis of Bilastine.

The present disclosure relates to methods of carbon-carbon bond fragmentation.

The present disclosure relates to methods of carbon-carbon bond fragmentation.

A method by which an intermediate product of an azole derivative can be produced at a lower cost than known production methods is provided. A method for producing a compound represented by General Formula (IV) includes converting a compound represented by General Formula (II) into the compound represented by General Formula (IV) using (a) dimethyl sulfide and/or dimethyl sulfoxide, and (b) a methyl-LG (an LG is a nucleophilically substitutable leaving group and is selected from the group consisting of a halogen group, an alkoxysulfonyloxy group, an aryloxysulfonyloxy group, an alkylsulfonyloxy group, a haloalkylsulfonyloxy group, and an arylsulfonyloxy group) in the presence of an inorganic base.

A method by which an intermediate product of an azole derivative can be produced at a lower cost than known production methods is provided. A method for producing a compound represented by General Formula (IV) includes converting a compound represented by General Formula (II) into the compound represented by General Formula (IV) using (a) dimethyl sulfide and/or dimethyl sulfoxide, and (b) a methyl-LG (an LG is a nucleophilically substitutable leaving group and is selected from the group consisting of a halogen group, an alkoxysulfonyloxy group, an aryloxysulfonyloxy group, an alkylsulfonyloxy group, a haloalkylsulfonyloxy group, and an arylsulfonyloxy group) in the presence of an inorganic base.

This invention relates to a method for the conversion of lignocellulosic biomass into ethyl esters of carboxylic acids. Said method consists of treating the biomass material with an oxidizing agent that is incorporated in an solution comprising one or more acids, one or more alcohols and water, and subsequently performing a catalytic reaction at a higher temperature using the same acidic solution into which a larger volume of alcohol is added, in such a way that the catalytic conversion occurs in a medium with a much higher concentration of alcohol, i.e. with a much higher alcohol-to-water wt ratio. Such a method results in relatively high yields of ethyl esters, such as ethyl esters of formic, acetic, and levulinic acids, while producing a low yield of dialkyl ethers, which are unwanted by-products. The concentration of the oxidizing agent in the pre-treatment step is preferably higher than 6.0 wt %. The oxidizing agent is preferably a Fenton or Fenton-type reagent, and most preferably hydrogen peroxide activated by Fe (II), and/or Ti (IV) ions. The alcohol is preferably ethanol, and when ethanol is used, diethyl ether is formed as the unwanted dialkyl ether by-product. Preferably, the biomass material is pelleted before treatment.

This invention relates to a method for the conversion of lignocellulosic biomass into ethyl esters of carboxylic acids. Said method consists of treating the biomass material with an oxidizing agent that is incorporated in an solution comprising one or more acids, one or more alcohols and water, and subsequently performing a catalytic reaction at a higher temperature using the same acidic solution into which a larger volume of alcohol is added, in such a way that the catalytic conversion occurs in a medium with a much higher concentration of alcohol, i.e. with a much higher alcohol-to-water wt ratio. Such a method results in relatively high yields of ethyl esters, such as ethyl esters of formic, acetic, and levulinic acids, while producing a low yield of dialkyl ethers, which are unwanted by-products. The concentration of the oxidizing agent in the pre-treatment step is preferably higher than 6.0 wt %. The oxidizing agent is preferably a Fenton or Fenton-type reagent, and most preferably hydrogen peroxide activated by Fe (II), and/or Ti (IV) ions. The alcohol is preferably ethanol, and when ethanol is used, diethyl ether is formed as the unwanted dialkyl ether by-product. Preferably, the biomass material is pelleted before treatment.

The present invention provides a process for preparing a (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3), wherein R represents a linear or branched alkyl group having 1 to 4 carbon atoms, the process comprising subjecting a haloacetaldehyde alkyl 2,3-dimethyl-2-cyclopentenyl acetal compound of the following general formula (1), wherein R is as defined above, and Y represents a halogen atom, to a dehydrohalogenation reaction in the presence of a base, followed by a rearrangement reaction to obtain a (1,2-dimethyl-2-cyclopentenyl)acetate compound of the following general formula (2), wherein R is as defined above, and subjecting the (1,2-dimethyl-2-cyclopentenyl)acetate compound (2) to an epoxidation reaction, followed by an isomerization reaction and then a methylenation reaction to obtain the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3). The present invention also provides a process for preparing (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde of the following formula (4), the process comprising the aforesaid process for preparing the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3), and converting an alkoxycarbonylmethyl group (i.e., —CH.sub.2C(═O)OR) of the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3) to a formylmethyl group (i.e., —CH.sub.2CHO) to obtain (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde (4). ##STR00001##