An efficient synthesis of a spirocyclic oxindole analogue.
An efficient, scaleable synthesis approach towards the spirocyclic oxindole analogue 1'-(tert-butoxycarbonyl)-2-oxospiro[indoline-3,4'-piperidine]-5-carboxylic acid (1) is described. The key steps are dianion alkylation and cyclization of ethyl 2- oxindoline-5-carboxylate (4) and demethylation of the resulting spirocyclic oxindole ethyl 1'-methyl-2-oxospiro[indoline-3,4'-piperidine]-5-carboxylate (5). The target compound was obtained in an overall yield of 35 % over eight steps without resorting to chromatographic purification.
Teng
Dawei
D
Department of Chemistry, ChemRoutes Corporation, Edmonton, Alberta T6E 5P8, Canada. tengdw@yahoo.com
Zhang
Hongxing
H
Mendonca
A
A
D000478:Alkylation; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D008745:Methylation; D000078183:Oxindoles; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D007211:Indoles; D000078183:Oxindoles; D013141:Spiro Compounds; C022960:2-oxindole