Stype 2-substituted hydroxy-2-indolidinylbutyric ester compounds and process for preparation thereof
AssigneeTanabe Seiyaku Co., Ltd.
InventorsTakayuki Kawaguchi, Sumihiro Nomura, Kenji Tsujihara
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Abstract
A process for preparing S type 2-substituted hydroxy-2-indolidinylbutyric ester compound [II]: 1 wherein Ro is residue of nitrogen-containing fused heterocyclic carboxylic acid having absolute configuration of “R” (in which the nitrogen atom is protected), R1 and R2 are lower alkyl groups, and E is ester residue, which is useful as an intermediate for preparing camptothecin derivatives having antitumor activities, which comprises 2-ethylating 2-substituted hydroxy-2-indolidinylacetic ester compound [I]: 2 wherein the symbols are as defined above.
Claims6
A process for preparing an S type 2-substituted hydroxy-2-indolidinylbutyric ester compound of the formula [II]:
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- wherein R0 is a residue of a nitrogen-containing fused heterocyclic carboxylic acid having an absolute configuration of “R” which is obtained by removing hydroxy group from the carboxyl group of said carboxylic acid (in which the nitrogen atom contained in the residue is protected), R1 and R2 are a lower alkyl group, and E is an ester residue, which comprises reacting a 2-halo-2-indolidinylacetic ester compound of the formula [III]:
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- wherein x is a halogen atom, and R1, R2 and E are as defined above, with an R type nitrogen-containing fused heterocyclic carboxylic acid compound of the formula [IV]:
- wherein Ro is as defined above, or a salt thereof to give a 2-substituted hydroxy-2-indolidinylacetic ester compound of the formula [I]:
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- wherein the symbols are as defined above, and then ethylating 2-position of the resultant compound [I].
A nitrogen-containing fused heterocyclic carboxylic acid having an absolute configuration of “R” of the formula [XIX]:
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- wherein Y is substituted or unsubstituted arylsulfonyl group or an alkylsulfonyl group, and n is 0 or 1, or a salt thereof.
Dependencies are inferred from the claim text.