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In methanol; hexanes; acetonitrile; at 0 - 20℃; |
To a slurry of the product of Step 7 (16 g, 75.5 mmol) in MeOH-MeCN (30 mL/300 mL) at 0 C. was added dropwise 60 mL of 2 M solution of TMSCHN2 in hexanes (120 mmol). The reaction mixture was allowed to warm to room temperature; then it was stirred for 14 h. The solution was then concentrated and the resulting solid was recrystallized from EtOAc (about 50 mL) to give 8.1 g of the desired product which was washed with 25% EtOAc in hexanes (3×20 mL). The mother liquors were concentrated and purified by flash column chromatography (SiO2, eluted with 16% EtOAc in hexanes) to provide 3.2 g of the desired product as a solid. 1H NMR (400 MHz, CDCl3) delta ppm 4.05 (s, 3H), 7.67 (dd, J=9.06, 2.01 Hz, 1H), 7.80 (s, 1H), 8.16 (d, J=8.81 Hz, 1H), 8.23 (d, J=2.01 Hz, 1H); 13C NMR (100 MHz, DMSO-d6) delta ppm 56.68, 122.70, 123.99, 124.14, 126.67, 127.83, 131.43, 134.10, 139.75, 149.94; LC-MS, MS m/z 229 (M++H). |
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In methanol; hexanes; acetonitrile; at 0 - 20℃; |
Step 8: To a slurry of the product of Step 7, Example 2 (16 g, 75.5 mmol) in MeOH-MeCN (30 mL/300 mL) at 0 0 C was added dropwise 60 ml of 2 M solution of TMSCHN2 in hexanes (120 mmol). The reaction mixture was allowed to warm to room temperature, then stirred for 14 h. The solution was then concentrated and the resulting solid was recrystallized from EtOAc (about 50 mL) to give 8.1 g of the desired product which was washed with 25% EtOAc in hexances; 20×3 times. The mother liquid was concentrated and purified by Biotage (elution with 16% EtOAc in hexanes) to provide 3.2 g of the desired product as a solid. 1H NMR (400 MHz, CDCl3) delta ppm 4.05 (s, 3H), 7.67 (dd, J=9.06, 2.01 Hz, 1H), 7.80 (s, 1H), 8.16 (d, J=8.81 Hz, 1H), 8.23 (d, J=2.01 Hz, 1H); 13C NMR (100 MHz, DMSO-d6) delta ppm 56.68, 122.70, 123.99, 124.14, 126.67, 127.83, 131.43, 134.10, 139.75, 149.94; LC-MS, MS m/z 229. |
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In methanol; hexanes; acetonitrile; at 0 - 20℃; for 14h; |
Step 8:; To a slurry of the product of Step 7 (16 g, 75.5 mmol) in MeOH-MeCN (30 mL/300 mL) at 0 C. was added dropwise 60 ml of 2 M solution of TMSCHN2 in hexanes (120 mmol). The reaction mixture was allowed to warm to room temperature, then stirred for 14 h. The solution was then concentrated and the resulting solid was recrystallized from EtOAc (about 50 mL) to give 8.1 g of the desired product which was washed with 25% EtOAc in hexances; 20×3 times. The mother liquid was concentrated and purified by Biotage (elution with 16% EtOAc in hexanes) to provide 3.2 g of the desired product as a solid.1H NMR (400 MHz, CDCl3) delta ppm 4.05 (s, 3H), 7.67 (dd, J=9.06, 2.01 Hz, 1H), 7.80 (s, 1H), 8.16 (d, J=8.81 Hz, 1H), 8.23 (d, J=2.01 Hz, 1H); 13C NMR (100 MHz, DMSO-D6) delta ppm 56.68, 122.70, 123.99, 124.14, 126.67, 127.83, 131.43, 134.10, 139.75, 149.94; LC-MS, MS m/z 229. |