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Chapter 2
Synthesis of substituted pyrimidines via Wittig
Figure-28
Peter Shu-Wai Leung et al. 50 have developed chromatography free Wittig
reaction by utilizing newly prepared bifunctional polymeric reagents , in this
phosphine and amine functionalized material was used in one-pot Wittig reactions
with an aldehyde and either an r-halo-ester, -ketone, or -amide. Due to the
heterogeneous nature of the polymer, the desired alkene product of these reactions
could be isolated in excellent yield in essentially pure form (Figure-29).
Figure-29
A. El-Batta et al. 51 was carried out Wittig reactions in water media employing
stabilized ylides with aldehydes. They described the use of a saturated aqueous
NaHCO 3 solution to achieve the aqueous one pot Wittig reactions at +20 to 90°Cusing
Ph 3 P, R-bromoesters, and aromatic carboxaldehydes (Figure-30).
Figure-30
Department of Chemistry, Saurashtra university, Rajkot-360005 54