反应详情

Example 48(a) was prepared in a similar manner as Example 41(a) from the starting material described below. 1H NMR (300 MHz, CD3OD) δ 8.54 (d, 1H, J=4.8 Hz), 7.95 (d, 1H, J=9.49 Hz), 7.84 (td, 1H, 1=7.71 Hz, =1.78 Hz), 7.70 (d, 1H, J=7.95 Hz), 7.53 (d, 1H, J=16.59 Hz), 7.40 (d, 1H, J=7.92 Hz), 7.29 (qd, 1H, 1=7.45 Hz, J=1.07 Hz), 7.11 (d, 1H, 1=11.8), 7.03-7.06 (m, 2H), 6.71 (s, 1H), 4.50 (q, 2H, J=7.16 Hz), 2.27 (s, 3H), 2.26 (s, 3H), 1.38 (t, 3H, 1=7.11 Hz). MS (ESI+) [M+H]/z Calc'd 496, found 496. Anal. Calc'd: C, 67.86; H, 5.29; N, 19.79. Found: C, 66.24; H, 5.50; N, 18.61. The starting material was prepared as follows: A mixture of 1-fluoro-5-methyl-2,4-dinitro-benzene (1.0 g, 5 mmol) and 10% Pd/C (200 mg) in MEOH (20 ml) was hydrogenated at 23° C. for 24 h. The reaction mixture was filtered through celite and concentrated. Purification by silica gel chromatography (1:1 ethyl acetate-hexane) gave 4-fluoro-6-methyl-benzene-1,3-diamine (613 mg, 87%). To a solution of carbonic acid 4-nitro-phenyl ester 2-trimethylsilanyl-ethyl ester (566 mg, 2 mmol) in DMF (4 ml) at 23° C. under an atmosphere of argon was added DMAP (12 mg. 0.1 mmol), DIEA (0.35 ml, 2 mmol) and 4-fluoro-6-methyl-benzene-1,3-diamine. The resulting solution was heated to 50° C. for 48 h. The reaction mixture was quenched with saturated NaHCO3 (aq), extracted with EtOAc (3×20 ml). The EtOAc was removed in-vacuo, and the residue was re-dissolved in Et2O then washed with 3 N NaOH (aq), water, brine, dried with Na2SO4, filtered and concentrated. Purification by silica gel chromatography (2:8-7:3 ethyl acetate-hexane) gave (5-amino-4-fluoro-2-methyl-phenyl)carbamic acid 2-trimethylsilanyl-ethyl ester (160 mg, 28%). MS (ESI+) [M+H]/z Calc'd 634, found 634.

1. customExample 48(a) was prepared in a similar manner as Example 41(a) from the starting material
2. customThe starting material was prepared
3. filtrationThe reaction mixture was filtered through celite and
4. concentrationconcentrated
5. customPurification by silica gel chromatography (1:1 ethyl acetate-hexane)