Synthesis and Cyclizations of N-(2,3-, 3,4- and 3,5-Dimethylphenyl)-β-alanines

Abstract

A series of 1-aryl substituted dihydro-, 5-methyldihydro- and 6-methyl-dihydro-2,4(1H,3H)pyrimidinediones and their 2-thio analogues were obtained byreaction of the corresponding β-alanines or α-methyl- and β-methyl-β-alanines with ureaor potassium thiocyanate. The reaction of N-(2,3- and 3,5-dimethylphenyl)-α-methyl-β-alanines with ethyl acetoacetate gave 1-(2,3- or 3,5-dimethylphenyl)-2,5-dimethyl-1,4,5,6-tetrahydro-4(1H)pyridones. The combined spectral data obtained by 1H-, 13C-,1 H/13C (HETCOR) NMR and IR provided useful information about the structure of theproducts synthesized in this work.

Keywords

• N-Aryl-β-alanines
• 1-aryl substituted dihydropyrimidinedione
• dihydro- pyrimidinone-2-thione
• 1
• 4
• 5
• 6-tetrahydropyridone
• NMR spectra
• IR spectra