Solid-phase synthesis of 2-substituted 4-amino-7-oxo-5,6,7,8-tetrahydropyrido[2,3-d]pyrimidines: an example of cyclization-assisted cleavage.

An efficient solid-phase synthesis of 2-substituted 4-aminopyrido[2,3-d]pyrimidines 12 by cyclization-assisted cleavage from resin is reported. The procedure starts by solid supporting an alpha,beta-unsaturated acid 8 to the Wang resin 13 by using DCC and 4-DMAP in THF. The resulting alpha,beta-unsaturated ester 14 is converted to the Michael adduct by treatment with malononitrile in NaOMe/THF.

Preparative-scale synthesis of two metabolites isolated from soil treated with zoxium fungicide and kerb herbicide.

The preparation in multigram scale of two metabolites 3-(3,5-dichloro-4-methyl-benzoylamino)-2-hydroxy-3-methyl-pentanoic acid and 3-(3,5-dichloro-benzoylamino)-3-methyl-2-oxo-butyric acid isolated from soil treated with either Zoxium fungicide or Kerb herbicide was efficiently accomplished using a common 5-step synthetic process starting from easily available raw materials.