The present invention relates to a continuous method for the preparation of (S)-2-acetyloxypropionic acid from an aqueous solution of lactic acid and acetic anhydride, in acetic acid. (S)-2-acetyloxypropionic acid is used for the preparation of (S)-2-acetyloxypropionic acid chloride, an essential intermediate compound for the preparation of lopamidol and has to be industrially produced with high purity and suitable quality for producing lopamidol according to the Pharmacopoeia requirements. The continuous process according to the invention, comprises therefore also the chlorination steps of (S)-2-acetyloxypropionic acid with thionyl chloride to give the corresponding (S)-2-acetyloxypropionic acid chloride which is further distilled to give the suitable purity characteristics for its use for the preparation of non-ionic iodinated contrast agents as lopamidol.

Provided is a labeling method having a step of labeling a substrate having a carbon-hydrogen bond with an oxygen isotope by using a catalyst and an oxidant produced from a hypervalent iodine compound having an ester structure and labeled water labeled with at least one oxygen isotope selected from the group consisting of .sup.17O and .sup.18O. Also provided is an oxidant for labeling that is produced from a hypervalent iodine compound having an ester structure and labeled water labeled with at least one oxygen isotope selected from the group consisting of .sup.17O and .sup.18O and labels a substrate having a carbon-hydrogen bond with an oxygen isotope in the co-presence of a catalyst.

The present invention provides a scalable synthesis of enantiomerically pure brivaracetam, and related derivatives.

The present invention provides a scalable synthesis of enantiomerically pure brivaracetam, and related derivatives.

A catalyst is prepared in situ by reaction between an aryl halide and a Ni(0) complex. The catalyst may be used to promote chain-growth polymerization of halogen-substituted Mg or Zn monomers by a controlled radical mechanism. Polymers, co-polymers, block copolymers, polymer thin films, and surface-confined polymer brushes may be produced using the catalyst.

A photoresist composition comprising: a resin having an acid-labile group, an acid generator, and a compound represented by formula (I): ##STR00001##
wherein R.sup.1, R.sup.2 and R.sup.3 each independently represents a C1-C24 hydrocarbon group in which a hydrogen atom can be replaced by a substituent and in which a methylene group can be replaced by an oxygen atom, a sulfur atom or a carbonyl group.

A photoresist composition comprising: a resin having an acid-labile group, an acid generator, and a compound represented by formula (I): ##STR00001##
wherein R.sup.1, R.sup.2 and R.sup.3 each independently represents a C1-C24 hydrocarbon group in which a hydrogen atom can be replaced by a substituent and in which a methylene group can be replaced by an oxygen atom, a sulfur atom or a carbonyl group.