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Boc Protection

(Boc2O + DMAP)







Examples:


Example 1



A solution of the SM (1.0 equiv), (Boc)2O (2.2 equiv), and DMAP (0.2 equiv), in DCM (0.15M) was stirred at RT for 16 h. Silica gel was added upon concentration and purification by silica gel chromatography (10% EtOAc/hexane) provided the product. [83%]


[Patent Reference: WO2010026121, page 39, (3.6 MB)]



Example 2


Boc Protection Reaction 8


To the SM (1.0 g, 3.94 mmol) in THF (20 mL) was added (Boc)2O (1.074 g, 4.92 mmol) and DMAP (48 mg, 0.39 mmol). The reaction mixture was stirred at RT under N2 for 4 days, after which time it was concentrated in vacuo, adsorbed on silica gel, and purified by column chromatography (0-25% EtOAc/hexane) to provide the product. [1.33 g]


[Patent Reference: WO2010038081, page 253, (33.8 MB)]



Example 3



A mixture of the SM (40 mg, 0.19 mmol), (Boc)2O (41 mg, 0.19 mmol), DMAP (2.3 mg, 0.02 mmol) in DCM (3 mL) was stirred at RT overnight, after which time TLC (EtOAc) indicated the complete consumption of the SM. The reaction mixture was washed with H2O, brine, dried (Na2SO4), and concentrated to provide the pdt as a white solid. [30 mg, 51%]


[Patent Reference: WO2010027500, page 105, (22.8 MB)]



Example 4



To a solution of the SM (250 mg, 0.7 mmol) in dioxane (10 mL) was added (Boc)2O (314 mg, 1.4 mmol) and DMAP (catalytic amt). The reaction mixture was stirred at 60 C for 12 h, after which time the mixture was partitioned between EtOAc (100 mL) and H2O (50 mL). The org layer was washed with NaHCO3 (50 mL), dried (Na2SO4), and concentrated in vacuo. The resulting material was purified by silica gel column chromatography to provide the product as a gummy liquid. [200 mg, 44%]


[Patent Reference: WO2014149164, page 289, (23.7 MB)]



Example 5



A mixture of the SM (14 g, 39.2 mmol), Boc2O (16.9 g, 78.3 mmol), DMAP (2.37 g, 19.6 mmol), and DCM (200 mL) was stirred at RT for 12 h. The mixture was diluted with DCM (200 mL), washed with H2O (2 x 300 mL), brine, dried (Na2SO4), and concentrated. The crude material was purified by silica gel chromatography (10-50% EtOAc/hexane) to provide the product as a yellow solid. [11.8 g, 91%]


[Patent Reference: WO2015140133, page 99, (11.7 MB)]