A process for preparing dialkyl terephalate comprising the following steps:—i) providing furan-2,5-dicarboxylate; ii) esterifying the furan-2,5-dicarboxylate with alcohol to form furan-2,5-carboxylic acid dialkyl ester; iii) reacting the furan-2,5-carboxylic acid dialkyl ester with ethylene under Diels Alder conditions, elevated temperature and pressure and in the presence of a catalyst such that dialkyl terephthalate is produced; wherein the Diels-Alder reaction is free from solvent; wherein the catalyst comprises a clay comprising metal ions and having Lewis acidity.

A process for preparing dialkyl terephalate comprising the following steps:—i) providing furan-2,5-dicarboxylate; ii) esterifying the furan-2,5-dicarboxylate with alcohol to form furan-2,5-carboxylic acid dialkyl ester; iii) reacting the furan-2,5-carboxylic acid dialkyl ester with ethylene under Diels Alder conditions, elevated temperature and pressure and in the presence of a catalyst such that dialkyl terephthalate is produced; wherein the Diels-Alder reaction is free from solvent; wherein the catalyst comprises a clay comprising metal ions and having Lewis acidity.

A process for preparing dialkyl terephalate comprising the following steps:—i) providing furan-2,5-dicarboxylate; ii) esterifying the furan-2,5-dicarboxylate with alcohol to form furan-2,5-carboxylic acid dialkyl ester; iii) reacting the furan-2,5-carboxylic acid dialkyl ester with ethylene under Diels Alder conditions, elevated temperature and pressure and in the presence of a catalyst such that dialkyl terephthalate is produced; wherein the Diels-Alder reaction is free from solvent; wherein the catalyst comprises a clay comprising metal ions and having Lewis acidity.

An object of the present invention is to provide a novel method for producing a fluorine-containing methylene compound. The above object can be achieved by a method for producing a compound represented by formula (1): ##STR00001##
wherein R.sup.1 represents an organic group, R.sup.A represents hydrogen or fluorine, R.sup.4a represents hydrogen or an organic group, R.sup.4b represents hydrogen or an organic group, R.sup.5a represents hydrogen or an organic group, R.sup.5b represents hydrogen or an organic group, and
R.sup.2 represents hydrogen or an organic group; R.sup.2 is optionally connected to R.sup.4a to form a ring; the method comprising step A of reacting a compound represented by formula (2): ##STR00002##
wherein X.sup.1 represents a leaving group, and other symbols are as defined above, with a compound represented by formula (3): ##STR00003##
wherein X.sup.2 represents a leaving group, and other symbols are as defined above, in the presence of a reducing agent as desired, under light irradiation.

An object of the present invention is to provide a novel method for producing a fluorine-containing methylene compound. The above object can be achieved by a method for producing a compound represented by formula (1): ##STR00001##
wherein R.sup.1 represents an organic group, R.sup.A represents hydrogen or fluorine, R.sup.4a represents hydrogen or an organic group, R.sup.4b represents hydrogen or an organic group, R.sup.5a represents hydrogen or an organic group, R.sup.5b represents hydrogen or an organic group, and
R.sup.2 represents hydrogen or an organic group; R.sup.2 is optionally connected to R.sup.4a to form a ring; the method comprising step A of reacting a compound represented by formula (2): ##STR00002##
wherein X.sup.1 represents a leaving group, and other symbols are as defined above, with a compound represented by formula (3): ##STR00003##
wherein X.sup.2 represents a leaving group, and other symbols are as defined above, in the presence of a reducing agent as desired, under light irradiation.

An object of the present invention is to provide a novel method for producing a fluorine-containing methylene compound. The above object can be achieved by a method for producing a compound represented by formula (1): ##STR00001##
wherein R.sup.1 represents an organic group, R.sup.A represents hydrogen or fluorine, R.sup.4a represents hydrogen or an organic group, R.sup.4b represents hydrogen or an organic group, R.sup.5a represents hydrogen or an organic group, R.sup.5b represents hydrogen or an organic group, and
R.sup.2 represents hydrogen or an organic group; R.sup.2 is optionally connected to R.sup.4a to form a ring; the method comprising step A of reacting a compound represented by formula (2): ##STR00002##
wherein X.sup.1 represents a leaving group, and other symbols are as defined above, with a compound represented by formula (3): ##STR00003##
wherein X.sup.2 represents a leaving group, and other symbols are as defined above, in the presence of a reducing agent as desired, under light irradiation.

The invention relates to fused cyclooctyne compounds, and to a method for their preparation. The invention also relates to a conjugate wherein a fused cyclooctyne compound according to the invention is conjugated to a label, and to the use of these conjugates in bioorthogonal labeling, imaging and/or modification, such as for example surface modification, of a target molecule. The invention further relates to a method for the modification of a target molecule, wherein a conjugate according to the invention is reacted with a compound comprising a 1,3-dipole or a 1,3-(hetero)diene.

The invention relates to fused cyclooctyne compounds, and to a method for their preparation. The invention also relates to a conjugate wherein a fused cyclooctyne compound according to the invention is conjugated to a label, and to the use of these conjugates in bioorthogonal labeling, imaging and/or modification, such as for example surface modification, of a target molecule. The invention further relates to a method for the modification of a target molecule, wherein a conjugate according to the invention is reacted with a compound comprising a 1,3-dipole or a 1,3-(hetero)diene.

The invention relates to fused cyclooctyne compounds, and to a method for their preparation. The invention also relates to a conjugate wherein a fused cyclooctyne compound according to the invention is conjugated to a label, and to the use of these conjugates in bioorthogonal labeling, imaging and/or modification, such as for example surface modification, of a target molecule. The invention further relates to a method for the modification of a target molecule, wherein a conjugate according to the invention is reacted with a compound comprising a 1,3-dipole or a 1,3-(hetero)diene.

##STR00001##

Disclosed herein is a salt of formula I: where R.sup.1, X, n, R, R.sup.1, Y, m, p, q, Z and o are as defined herein. Also disclosed herein are methods of using said salts in chemical synthesis, such as to prepare compounds isotopically enriched in 18F for use in PET & imaging, as well as methods to make the compounds of formula I.