Synthesis of diverse N-acyl-pyrazoles via cyclocondensation of hydrazides with α-oxeketene dithioacetal

Mol Divers. 2017 Nov;21(4):1021-1026. doi: 10.1007/s11030-017-9771-6. Epub 2017 Aug 8.

Abstract

An elegant, efficient, and highly regioselective approach for the synthesis of novel methyl 5-amino-3-(methylthio)-1-differently substituted-1H-pyrazole-4-carboxylates is reported. The procedure involves the cyclocondensation of α-oxeketene S, S-dimethyl acetal building blocks with different alkyl, aryl, and heterocyclic acid hydrazides. The novel molecules were obtained in good yields and their identities confirmed by NMR and HRMS spectrometry.

Keywords: Heterocycles; Hydrazides; Itaconic acid; Oxeketene; Pyrazoles; Pyrrolidinones.

MeSH terms

  • Acetals / chemistry*
  • Chemistry Techniques, Synthetic
  • Ethylenes / chemistry*
  • Hydrazines / chemistry*
  • Ketones / chemistry*
  • Nitrogen / chemistry*
  • Pyrazoles / chemical synthesis*
  • Pyrazoles / chemistry*
  • Stereoisomerism

Substances

  • Acetals
  • Ethylenes
  • Hydrazines
  • Ketones
  • Pyrazoles
  • hydrazine
  • ketene
  • Nitrogen