A mixture of 5.0 g (21.4 mmol) of 3,5-di-t-butyl-4-hydroxy benzaldehyde, 2.34 g (21.6 mmol) of 3-picolylamine and 6.0 g (42.8 mmol) anhydrous potassium carbonate in 50 ml benzene was refluxed for one day. The potassium carbonate was filtered and the solvent was evaporated. The residue was heated at 140° C. with 3.0 g (21.6 mmol) of diethylphosphite for 3 h. An amount of 6.6 g of compound was isolated by column chromatography (95/5 CHCl13 /MeOH), which gave 5.9 g (60%) after recrystallization in petroleum ether; mp=100°-101 ° C. IR (film): 3650 cm-1 :OH, 3300 (large): NH, 1430: tert-Bu, 1230: P=O, 1030: P--O--C, NMR (CDCl3): δ=8.50, 7.65 and 7.25 (3 m, 4H): aromatic H, 3-picolyl 7.20 (d, JP-H =2 Hz, 2H): aromatic H, 3,5-di-butyl-4-hydroxyphenyl 5.25 (s, 1H): OH 4.08, 3.94 and 3.80 (3m, 4H): P--O--CH2CH3 3.91 (d, JP-H =19 Hz, 1H): CH--PO3Et2 3.81 and 3.61 (2d, J=13 Hz, 2H): NH--CH2 --Py 2.20 (broad): NH-, 1.45 (s, 18H): tert-Bu 1.30 and 1.10 (2t, J=7 Hz, 6H): P--O--CH2CH3MS: m/e=462: M+, 324:M+ --HPO3Et2 (base peak) Elemental analysis C25H39N2O4P % Calc C 64.91 H 8.50 N 6.06 P 6.70 % Found C 64.83 H 8.70 N 5.88 P 6.45
