Method for visible-light driven oxidation of aldehydes to carboxylic acid using carbon dioxide (CO.sub.2) as the oxidant in the absence of any catalyst are provided. In the disclosed process, aldehydes, when reacted with CO.sub.2 in an organic solvent, either in a batch reactor or in a continuous flow reactor, under conditions of ambient temperature and pressure, using a readily available household LED lamp, yield corresponding carboxylic acids along with the formation of carbon monoxide (CO) in the effluent gas.

Method for visible-light driven oxidation of aldehydes to carboxylic acid using carbon dioxide (CO.sub.2) as the oxidant in the absence of any catalyst are provided. In the disclosed process, aldehydes, when reacted with CO.sub.2 in an organic solvent, either in a batch reactor or in a continuous flow reactor, under conditions of ambient temperature and pressure, using a readily available household LED lamp, yield corresponding carboxylic acids along with the formation of carbon monoxide (CO) in the effluent gas.

Method for visible-light driven oxidation of aldehydes to carboxylic acid using carbon dioxide (CO.sub.2) as the oxidant in the absence of any catalyst are provided. In the disclosed process, aldehydes, when reacted with CO.sub.2 in an organic solvent, either in a batch reactor or in a continuous flow reactor, under conditions of ambient temperature and pressure, using a readily available household LED lamp, yield corresponding carboxylic acids along with the formation of carbon monoxide (CO) in the effluent gas.

The present invention relates to a method for preparing 4,4′-dihydroxy-[1,1′-biphenyl-3,3′-dicarboxylic acid], the method comprising a step for preparing a compound represented by chemical formula 1 by reacting a compound represented by chemical formula 2 with a base according to reaction formula 1. [reaction formula 1] [chemical formula 1] [chemical formula 2] According to the present invention, because use of additional carbon dioxide is unnecessary during the reaction, internal pressure is lowered during same, the reaction can be carried out at a lower temperature, the yield from the synthesis is notably improved as hardening of the resulting substance is absent, and H.sub.4dobpdc can be synthesized in large amounts as an additional process for obtaining pure ligands is unnecessary.

The present invention relates to a method for preparing 4,4′-dihydroxy-[1,1′-biphenyl-3,3′-dicarboxylic acid], the method comprising a step for preparing a compound represented by chemical formula 1 by reacting a compound represented by chemical formula 2 with a base according to reaction formula 1. [reaction formula 1] [chemical formula 1] [chemical formula 2] According to the present invention, because use of additional carbon dioxide is unnecessary during the reaction, internal pressure is lowered during same, the reaction can be carried out at a lower temperature, the yield from the synthesis is notably improved as hardening of the resulting substance is absent, and H.sub.4dobpdc can be synthesized in large amounts as an additional process for obtaining pure ligands is unnecessary.

The present invention relates to a method for preparing 4,4′-dihydroxy-[1,1′-biphenyl-3,3′-dicarboxylic acid], the method comprising a step for preparing a compound represented by chemical formula 1 by reacting a compound represented by chemical formula 2 with a base according to reaction formula 1. [reaction formula 1] [chemical formula 1] [chemical formula 2] According to the present invention, because use of additional carbon dioxide is unnecessary during the reaction, internal pressure is lowered during same, the reaction can be carried out at a lower temperature, the yield from the synthesis is notably improved as hardening of the resulting substance is absent, and H.sub.4dobpdc can be synthesized in large amounts as an additional process for obtaining pure ligands is unnecessary.

A catalytic process for preparing an α,β-ethylenically unsaturated carboxylic acid salt, comprising a) contacting an alkene and carbon dioxide with a carboxylation catalyst, an organic solvent, and an alkoxide having a secondary or tertiary carbon atom directly bound to an [O.sup.−] group, to obtain a crude reaction product comprising the α,β-ethylenically unsaturated carboxylic acid salt and an alcohol by-product which is the conjugate acid of the alkoxide, b) allowing the α,β-ethylenically unsaturated carboxylic acid salt to precipitate out from the crude reaction product; and c) subjecting at least part of the crude reaction product to a mechanical separation step while maintaining the alcohol by-product in liquid form to obtain a solid phase comprising the α,β-ethylenically unsaturated carboxylic acid salt and a liquid phase comprising the carboxylation catalyst, the organic solvent and the alcohol by-product. The process allows for easy separation of the α,β-ethylenically unsaturated carboxylic acid salt by a mechanical separation operation.

A catalytic process for preparing an α,β-ethylenically unsaturated carboxylic acid salt, comprising a) contacting an alkene and carbon dioxide with a carboxylation catalyst, an organic solvent, and an alkoxide having a secondary or tertiary carbon atom directly bound to an [O.sup.−] group, to obtain a crude reaction product comprising the α,β-ethylenically unsaturated carboxylic acid salt and an alcohol by-product which is the conjugate acid of the alkoxide, b) allowing the α,β-ethylenically unsaturated carboxylic acid salt to precipitate out from the crude reaction product; and c) subjecting at least part of the crude reaction product to a mechanical separation step while maintaining the alcohol by-product in liquid form to obtain a solid phase comprising the α,β-ethylenically unsaturated carboxylic acid salt and a liquid phase comprising the carboxylation catalyst, the organic solvent and the alcohol by-product. The process allows for easy separation of the α,β-ethylenically unsaturated carboxylic acid salt by a mechanical separation operation.

A catalytic process for preparing an α,β-ethylenically unsaturated carboxylic acid salt, comprising a) contacting an alkene and carbon dioxide with a carboxylation catalyst, an organic solvent, and an alkoxide having a secondary or tertiary carbon atom directly bound to an [O.sup.−] group, to obtain a crude reaction product comprising the α,β-ethylenically unsaturated carboxylic acid salt and an alcohol by-product which is the conjugate acid of the alkoxide, b) allowing the α,β-ethylenically unsaturated carboxylic acid salt to precipitate out from the crude reaction product; and c) subjecting at least part of the crude reaction product to a mechanical separation step while maintaining the alcohol by-product in liquid form to obtain a solid phase comprising the α,β-ethylenically unsaturated carboxylic acid salt and a liquid phase comprising the carboxylation catalyst, the organic solvent and the alcohol by-product. The process allows for easy separation of the α,β-ethylenically unsaturated carboxylic acid salt by a mechanical separation operation.

The present invention generally relates to processes for purification, recovery, and conversion of chlorophenol salts (e.g., 2,5-dichlorophenol and salts thereof). In various aspects, the present invention is related to removing one or more impurities from chlorophenol salt-containing process streams and/or recovering chlorophenol salts from process streams for use of the recovered chlorophenol elsewhere in an integrated process. Process streams that may be treated in accordance with the present invention include those incorporating one or more chlorophenol salts in a feed mixture and also those where one or more chlorophenol salts are present in a product or by-product stream of an integrated process. For example, conversion processes of the present invention are suitable as one piece of an integrated process for producing 3,6-dichloro-2-methoxybenzoic acid (dicamba) or a salt or ester thereof or a process for producing 2,4-dichlorophenoxyacetic acid (2,4-D) or a salt or ester thereof. The present invention further relates to processes for preparation, purification, and recovery of intermediates formed in integrated processes utilizing chlorophenol salts such as 2,5-dichlorophenol as starting material, including the intermediate 3,6-dichlorosalicylic acid (3,6-DCSA) formed during preparation of dicamba from 2,5-dichlorophenol.