Reaction Steps
A mixture of 2.0 g of 6-bromo-2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidine, 2.1 g of diethyl N-(4-ethynylbenzoyl)-L-glutamate, 2.57 ml of triethylamine, 0.11 g of palladium chloride, 0.32 g of triphenylphosphine, and 0.05 g of cuprous chloride in 150 ml of acetonitrile is heated at reflux under nitrogen for 2.5 hours. The solid which forms upon first cooling to room temperature is collected by filtration, and washed with cold acetronitrile to yield 1.91 g of diethyl N-[4-(2-pivaloylamino-4-hydroxypyrido[2,3-d]pyrimidin-6-ylethynyl)benzoyl]-L-glutamate which is sufficiently pure for further processing. Chromatography on silica gel with 5% methanol:methylene chloride showing the following physical properties. m.p. >250° C.; NMR (CDCl3, 300 MHz) delta 1.25 (t, 3H, J=7.20 Hz), 1.33 (t, 3H, J=7.20 Hz), 1.36 (s, 9H), 2.14-2.62 (m, 4H), 4.14 (q, 2H, J= 7.20 Hz), 4.27 (q, 2H, J=7.20 Hz), 4.79-4.86 (m, 1H), 7.30 (d, 1H, J=8.40 Hz), 7.63 (d, 2H, J=8.25 Hz), 7.86 (d, 2H, J=8.25 Hz), 8.51 (brs, 1H), 8.64 (d, 1H, J=2.40 Hz), 8.97 (d, 1H, J=2.40 Hz), 12.2 (brs, 1H); IR (KBr) 3330, 3290, 2970, 1730, 1655, 1590, 1530, 1440, 1370, 1260, 1140, 1020, 965, 925, 850, 810, and 760 cm1 ; 13C-NMR (CDCl3, 75 MHz) delta 14.3, 27.1, 27.2, 30.7, 40.6, 52.7, 61.1, 62.0, 87.61, 92.71, 115.1, 117.3, 125.9, 127.4, 127.5, 132.0, 133.9, 138.7, 149.6, 157.8, 158.6, 160.5, 166.4 172.1, 173.5, 180.8. Anal. Calcd. for C30H33N5O7 : C, 62.60; H, 5.78; N, 12.35. Found: C, 44.56; H, 3.85; N, 17.30; Br, 24.38.
