Reactions of alkanolamines [R 1R 2NXOH;R 1 = H, CH 3, C 2H 5, C 4H t 9, C 6H 5; R 2 = H; CH 3,C 2H 5 and X = -CH 2CH 2-, -CH 2CH 2CH 2-, -CH 2CHCH 3, -C 6H 4CH 2CH 2-, -CH 2CH 2SCH 2CH 2-] with ethyl borate in different molar ratios (1 to 3) yield the trisproduct only. All the derivatives are distillable liquids, soluble in common organic solvents and susceptible to hydrolysis even by atmospheric moisture. The new derivatives are characterized by elemental analyses, I.R. 1H NMR spectra, refractive indices and molecular weight measurements.