[C:1]1([P:7]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[C:8]2[N:13]=[C:12]([NH2:14])[CH:11]=[CH:10][CH:9]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C(N(CC)CC)C.[C:28](Cl)(=[O:33])[C:29]([CH3:32])([CH3:31])[CH3:30]>ClCCl.CN(C)C1C=CN=CC=1>[C:15]1([P:7]([C:1]2[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=2)[C:8]2[N:13]=[C:12]([NH:14][C:28](=[O:33])[C:29]([CH3:32])([CH3:31])[CH3:30])[CH:11]=[CH:10][CH:9]=2)[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=12.0 g (7.2 mmol) of 6-(diphenylphosphino)-2-aminopyridine from example 14.3.1 were dissolved in 40 ml of dichloromethane and admixed with 1.6 ml (1.2 g, 10.8 mmol) of triethylamine and 0.16 g (0.7 mmol) of 4-dimethylaminopyridine (DMAP). After cooling to 0° C. (H2O/ice), 1.2 ml (1.2 g, 8.8 mmol) of pivaloyl chloride were slowly added dropwise and the mixture was kept at this temperature for 3 h. The mixture was allowed to warm to room temperature overnight and the solvent was then removed under reduced pressure. The residue was purified by filtration together with cyclohexane/ethyl acetate (1:1) through a short silica gel column (3×10 cm). The solvent was removed under reduced pressure and the resulting oil crystallized by digesting with petroleum ether (40/60). The solid was filtered off, washed with petroleum ether (40/60) and dried under reduced pressure. 2.25 g (6.2 mmol, 86.1%) of 6-(diphenylphosphino)-2-pivaloylaminopyridine were obtained as a beige-colored solid.
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