Synthesis of alkoxysilanes as starting substances for preparation of new materials by the sol-gel procedure. Silanes with urea functional group

New bis(triethoxysilanes) containing a urea functional group >NC(O)N< and having the comL, position (C2H5O)(3)Si(CH2)(3)NHC(O)NRR' [R = R' = n-C3H7; R = H, R' = (CH2)(3)Si(CH3)(OC2H5)(2)] and [(C2H5O)(3)Si(CH2)(3)NHC(O)NH](2)(C(n)A(m))(x) (A = H, x = 2, 4, 12, n = 1, m = 2; A = H, CH3, x = 1, n = 6, m = 4; A = H, x = 1, n = 10, In = 6) were prepared in high yields and with satisfactory purity by reactions of primary C amines (or diamines) with 3-(triethoxysilyl)propyl isocyanate.