[C:1](Cl)(Cl)=[O:2].[NH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[C:8]([CH3:12])[N:7]=1.C(N(CC)CC)C.[C:20]([OH:24])([CH3:23])([CH3:22])[CH3:21]>C(Cl)(Cl)Cl>[C:20]([O:24][C:1](=[O:2])[NH:5][C:6]1[CH:11]=[CH:10][CH:9]=[C:8]([CH3:12])[N:7]=1)([CH3:23])([CH3:22])[CH3:21]
295.7 g (199 mL) of chloroform were added to a reaction system and cooled to 0° C. followed by blowing in 43.08 g (0.436 moles) of phosgene over the course of 0.5 hours. A mixed solution containing 21.66 g (0.200 moles) of 2-amino-6-picoline, 20.26 g (0.200 moles) of triethylamine, 37.02 g (0.499 moles) of t-butanol and 89.6 g (60 mL) of chloroform were dropped into this phosgene solution over the course of 1.0 hours while holding the internal temperature at −3° C. to 2° C. Following completion of dropping, the solution was stirred for 1.4 hours. Next, 20.30 g (0.201 moles) of triethylamine and 59.4 g (40 mL) of chloroform were dropped in over the course of 0.8 hours while holding the internal temperature at 0° C. to 5° C. Following completion of dropping, the solution was stirred for 1.0 hours. Next, 122.5 g (82 mL) of chloroform were added. The reaction solution was subjected to quantitative analysis by HPLC. The target (6-methyl-pyridin-2-yl)-carbamic acid tert-butyl ester was obtained at a yield of 94%. The yield of 1,3-bis-(6-methyl-pyridin-2-yl)-urea (urea compound) was 2%.
Loading…
