Three-component reactions for the synthesis of substituted dihydropyrimidin
es (4), chromenes (8) and tetrahydroquinolines (11) have been performed in
water and in the presence of a montmorillonite KSF clay. The products, easi
ly isolated from the reaction mixture by crystallisation, are obtained in h
igh yield and selectivity and the catalyst can be recycled for many runs wi
thout losing its activity. (C) 2000 Elsevier Science B.V. All rights reserv
ed.