Synthesis of Si-containing cyclic ureas

1,3-Bis[(triethoxysilyl)methyl]tetrahydropyrimidin-2-one and 1,3-bis[(dimethoxysilyl)methyl]tetrahydro-pyrimidin-2-one have been synthesized on interacting urea with N,N′-bis(silylmethyl)propylenamines (EtO)3−nMenSiCH2NH(CH2)3NHCH2SiMen(OEt)3−n (n = 0, 2). Their interaction with boron trichloride has been studied. The structures of all the compounds synthesized have been demonstrated by multinuclear NMR spectroscopy.