The present invention relates to novel piperazine derivatives, methods for their preparation, pharmaceutical compositions including such compounds, and methods of using these compounds and compositions, especially for targeted therapy treatment of hyperproliferative disorders, including benign hyperproliferative disorders, cancer and pre-cancer conditions.

Provided are a method for producing a peptide compound including a step of using a compound represented by Formula (1); a protective group-forming reagent including the compound; and the compound. At least one of R.sup.1 to R.sup.8 or Y.sup.2 has R.sup.A, R.sup.A represents an aliphatic hydrocarbon group or an organic group having an aliphatic hydrocarbon group, and the number of carbon atoms in at least one aliphatic hydrocarbon group is 12 or more. However, R.sup.A does not have a silyl group and a hydrocarbon group having a silyloxy structure.

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The present invention relates to novel piperazine derivatives, methods for their preparation, pharmaceutical compositions including such compounds, and methods of using these compounds and compositions, especially for targeted therapy treatment of hyperproliferative disorders, including benign hyperproliferative disorders, cancer and pre-cancer conditions.

The present invention relates to novel piperazine derivatives, methods for their preparation, pharmaceutical compositions including such compounds, and methods of using these compounds and compositions, especially for targeted therapy treatment of hyperproliferative disorders, including benign hyperproliferative disorders, cancer and pre-cancer conditions.

The present invention relates to novel piperazine derivatives, methods for their preparation, pharmaceutical compositions including such compounds, and methods of using these compounds and compositions, especially for targeted therapy treatment of hyperproliferative disorders, including benign hyperproliferative disorders, cancer and pre-cancer conditions.

Provided are a method for producing a peptide compound including a step of using a compound represented by Formula (1); a protective group-forming reagent including the compound; and the compound. At least one of R.sup.1 to R.sup.8 or Y.sup.2 has R.sup.A, R.sup.A represents an aliphatic hydrocarbon group or an organic group having an aliphatic hydrocarbon group, and the number of carbon atoms in at least one aliphatic hydrocarbon group is 12 or more. However, R.sup.A does not have a silyl group and a hydrocarbon group having a silyloxy structure. ##STR00001##

Described are a compound of formula (II) or (III):

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The compounds are effective in the treatment of disease, including a tauopathy condition or a disease of tau protein aggregation.

Described are a compound of formula (II) or (III): ##STR00001## The compounds are effective in the treatment of disease, including a tauopathy condition or a disease of tau protein aggregation.