MS 50 mass spectrometers (70 eV). GS-MS couplings were performed by means of a Pye-Unicam gas chromatograph (SE 30,3%, 1.5 m) coupled with a A.E.I. MS 20 spectrometer. Compounds 2 and 3 were prepared as previously described.2'11 Melting points were measured with a Kofler hot stage and were uncorrected.Preparation of Triimidazo[l,3,5]triazine Derivatives 5 and 6. In a typical experiment, 5.0 g (0.025 mol) of 1-tertbutyl-5,5-dimethyl-4-methoxy-2-imidazolidinone (2d) was heated at 140 °C in vacuo (0.05 mm Hg) for 15 min. After cooling the crude product was dissolved in 50 mL of ether and filtered. The filtrate was concentrated and triturated with hexane. After standing overnight at -5 °C the crystals were isolated by filtration and washed with cold hexane.Recrystallization was performed from hexane. There was obtained 3.5 g of 3,7,1 l-tri-tert-butyl-4,4,8,8,12,12-hexamethyll/í,2fí,5//,6fí,9/í,10H-triimidazo[3,4-a;3,,4'-c;3",4"-e][l,3,5]triazine-2,6,10-trione (5d) (yield 84%): mp 224 °C; NMR (CDClg) 1.41 (18 H, s,), 1.48 (21 H, s), 1.53 (3 H, s), 1.72 (3 H, s) (all these singlets are due to resonances of N-t-Bu and CCCHgD, 3.76 (1 H, s), 4.52 (1 H, s), 5.00 (1 H, s) (the latter three singlets are resonances of N-CH-N).13C NMR (CDCI3). The <5 values (ppm) of 5d are given (noise decoupled); the multiplicities, given between brackets, were obtained from the off-resonance decoupled spectrum: 23.
