The invention is directed to a process for the ring-opening of a cycloadduct obtainable from a reaction of a furanic compound and a diene, said process comprising contacting the cycloadduct with an acidic mixture comprising sulfuric acid and an activating agent to obtain a ring-opened product. The present invention is particularly directed a continuous process.

The invention belongs to the pharmaceutical manufacturing field, which relates to a novel process for the preparation of substituted phenylacetic acids derivatives, especially relates to the preparation of 2-(4-(2-oxocyclopentyl)phenyl)propanoic acid. The process for the preparation of the precursor form of loxoprofen which use 1,4-di-halobenzyl compounds or disubstituted benzyl compounds as starting material, is through the substitution reaction of cyclopentanone groups or its precursor compounds.

##STR00001##

Wherein X is halogen, L.sub.1 is a suitable leaving group selected from halogen, OH, OMs, OTs, OTf and the like; L.sub.2 is a suitable leaving group selected from halogen, CN, OH, CH.sub.2OH, CHO, CH.sub.3NO.sub.2, ester group, NR.sub.4R.sub.5, OTf, OTs, OMs, CCR.sub.6, CCR.sub.7 and the like, wherein R.sub.4, R.sub.5, R.sub.6, R.sub.7 are short chain alkyl groups; Z is cyclopentanone group and its precursor form selected from

##STR00002##

and the like; R.sub.3 is short chain alkyl groups. L.sub.3 is a suitable leaving group selected from halogen, OH, OMs, OTs, OT.sub.f and the like, or organometallic groups. The invention also include the detailed procedure to convert the precursor compounds of cyclopentanone group to cyclopentanone, followed by the transformation of the precursor compounds of loxoprofen to loxoprofen.

The invention belongs to the pharmaceutical manufacturing field, which relates to a novel process for the preparation of substituted phenylacetic acids derivatives, especially relates to the preparation of 2-(4-(2-oxocyclopentyl)phenyl)propanoic acid. The process for the preparation of the precursor form of loxoprofen which use 1,4-di-halobenzyl compounds or disubstituted benzyl compounds as starting material, is through the substitution reaction of cyclopentanone groups or its precursor compounds.

##STR00001##

Wherein X is halogen, L.sub.1 is a suitable leaving group selected from halogen, OH, OMs, OTs, OTf and the like; L.sub.2 is a suitable leaving group selected from halogen, CN, OH, CH.sub.2OH, CHO, CH.sub.3NO.sub.2, ester group, NR.sub.4R.sub.5, OTf, OTs, OMs, CCR.sub.6, CCR.sub.7 and the like, wherein R.sub.4, R.sub.5, R.sub.6, R.sub.7 are short chain alkyl groups; Z is cyclopentanone group and its precursor form selected from

##STR00002##

and the like; R.sub.3 is short chain alkyl groups. L.sub.3 is a suitable leaving group selected from halogen, OH, OMs, OTs, OT.sub.f and the like, or organometallic groups. The invention also include the detailed procedure to convert the precursor compounds of cyclopentanone group to cyclopentanone, followed by the transformation of the precursor compounds of loxoprofen to loxoprofen.

Disclosed is a novel transition metal complex containing N-heterocyclic carbene and a sulfonamide group, or N-heterocyclic carbene and an amide group, and application thereof, the traquesnsition metal complex having a wider range of general purposes in olefin metathesis and being able to be variably controlled in reactivity.

Disclosed is a novel transition metal complex containing N-heterocyclic carbene and a sulfonamide group, or N-heterocyclic carbene and an amide group, and application thereof, the traquesnsition metal complex having a wider range of general purposes in olefin metathesis and being able to be variably controlled in reactivity.

Provided is a process for oxidizing an alkene. The process comprises contacting an alkene, and either an oxidizing electrophile comprising a main group element in oxidized form or an oxidant and a reduced form of the oxidizing electrophile, in a liquid medium comprising an oxygen acid and optionally one or more additives selected from a non-oxidizable liquid, a salt additive, a Lewis acid, and water, to provide an oxygenate and a reduced form of the oxidizing electrophile. The process optionally further comprises separating the oxygenate and the reduced form of the oxidizing electrophile. The oxygenate can be further hydrolyzed to form an alcohol, diol, or polyol.

Disclosed embodiments relate to improved methods for the synthesis of activated fumarate intermediates and their use in chemical synthesis. Disclosed embodiments describe the synthesis of activated fumarate esters including those derived from activating groups including: 4-nitrophenyl, diphenylphophoryl azide, pivaloyl chloride, chlorosulfonyl isocyanate, p-nitrophenol, MEF, trifluoroacetyl and chlorine, for example, ethyl fumaroyl chloride and the subsequent use of the activated ester in situ. Further embodiments describe the improved synthesis of substituted aminoalkyl-diketopiperazines from unisolated and unpurified intermediates allowing for improved yields and reactor throughput.

Disclosed embodiments relate to improved methods for the synthesis of activated fumarate intermediates and their use in chemical synthesis. Disclosed embodiments describe the synthesis of activated fumarate esters including those derived from activating groups including: 4-nitrophenyl, diphenylphophoryl azide, pivaloyl chloride, chlorosulfonyl isocyanate, p-nitrophenol, MEF, trifluoroacetyl and chlorine, for example, ethyl fumaroyl chloride and the subsequent use of the activated ester in situ. Further embodiments describe the improved synthesis of substituted aminoalkyl-diketopiperazines from unisolated and unpurified intermediates allowing for improved yields and reactor throughput.

Disclosed embodiments relate to improved methods for the synthesis of activated fumarate intermediates and their use in chemical synthesis. Disclosed embodiments describe the synthesis of activated fumarate esters including those derived from activating groups including: 4-nitrophenyl, diphenylphophoryl azide, pivaloyl chloride, chlorosulfonyl isocyanate, p-nitrophenol, MEF, trifluoroacetyl and chlorine, for example, ethyl fumaroyl chloride and the subsequent use of the activated ester in situ. Further embodiments describe the improved synthesis of substituted aminoalkyl-diketopiperazines from unisolated and unpurified intermediates allowing for improved yields and reactor throughput.

Disclosed are a method for preparing 2-(cyclohexenylidene) malonic acid derivatives and uses thereof. In this method, an olefin and a 2-substituted malonic acid derivative are used as starting materials to prepare the 2-(cyclohexenylidene) malonic acid derivative in the presence of a catalyst through cyclization reaction. This method has the following advantages: (1) the method can be very efficiently used for the synthesis of highly sterically-hindered 2-(2,6-disubstituted cyclohexenylidene) malonic acid derivatives; (2) the reaction yield is high, the reaction conditions are mild, and the wastes are less, favorable for industrial production. More importantly, the present invention extends the further use of 2-(cyclohexenylidene)malonic acid derivatives in organic synthesis, especially in the synthesis of 2-aryl malonic acid derivatives and their corresponding drugs such as Pinoxaden.