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US 2017/0247315 A1Published application
Novel process for the preparation of spiro[2.5]octane-5,7-dione and spiro[3.5]nonane-6,8-dione
AssigneeBoehringer Ingelheim International GmbH
InventorsXiangle XIN, Weitong DONG, Yan FU, Jun LU, Le XIE, Wei XU, Jinsong YANG, Qian ZHU
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Abstract
This invention relates to methods for the synthesis of spiro[2.5]octane-5, 7-dione and spiro[3.5]nonane-6, 8-dione which are useful as intermediates in the manufacture of pharmaceutically active ingredients.
Claims15
A method of preparing spiro[2.5]octane-5,7-dione having the formula
- said method
- either comprising:
- (a) cyclization of cyclopropylidene carboxylic acid alkyl ester having the formula
- with dialkyl 1,3-acetonedicarboxylate having the formula
- to form 5,7-dioxo-spiro[2.5]octane-4,6-dicarboxylic acid dialkyl ester having the formula
- wherein each R may be independently C1-C6 alkyl,
- and
- ester hydrolysis and decarboxylation of 5,7-dioxo-spiro[2.5]octane-4,6-dicarboxylic acid
- to form spiro[2.5]octane-5,7-dione,
- wherein each R may be independently C1-C6 alkyl,
- or
- (b) cyclization of [1-(2-oxo-propyl)cyclopropyl]acetic acid alkyl ester having the formula
- to form spiro[2.5]octane-5,7-dione, wherein R′ is C1-C6 alkyl.
10 more elements
A method of preparing spiro[3.5]nonane-6,8-dione having the formula
- said method:
- cyclization of cyclobutylidene carboxylic acid alkyl ester having the formula
- with dialkyl 1,3-acetonedicarboxylate having the formula
- to form 6,8-dioxo-spiro[3.5]nonane-5,7-dicarboxylic acid dialkyl ester having the formula
- wherein each R may be independently C1-C6 alkyl,
- and
- ester hydrolysis and decarboxylation of 6,8-dioxo-spiro[3.5]nonane-5,7-dicarboxylic acid dialkyl ester having the formula
- to form spiro[3.5]nonane-6,8-dione, wherein each R may be independently C1-C6 alkyl.
5 more elements
A process for the manufacture of spiro[2.5]octane-5,7-dione having the formula
- said process comprising the following reaction steps:
- wherein R and R′ are each independently C1-C6 alkyl.
A compound selected from the group consisting of:
- wherein R and R′ are each independently hydrogen or C1-C6 alkyl, or a tautomer or salt thereof.
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Dependencies are inferred from the claim text.