Water → 1-cyclopropyl-8-(diphenylmethoxycarbonylmethyl)-7-fluoro-9-methyl-4-oxo-4H-quinolizine-3-carboxylic acid ethyl ester

Participants

Reaction Steps

To a suspension of NaH in DMF with ice bath cooling is added di-t-butyl malonate. After the addition, 8-chloro-1-cyclopropyl-7-fluoro-9-methyl-4-oxo-4H-quinolizine-3-carboxylic acid ethyl ester from Example 253i above is added. The reaction is then heated to 50° to 60° C., and the mixture is poured into water and acidified. The product is extracted into methylene chloride and dried over MgSO4. The residue, after removal of the solvent, is dissolved in methylene chloride and trifluoroacetic acid at room temperature. The solvent is removed under vacuum, and the product is treated with diphenyldiazomethane in methylene chloride and methanol. When the reaction is finished, the solvents are removed under vacuum, and the product is purified by column chromatography to give the title compound.

Provenance & Evidence