Sandmeyer
(Ar-NH2 to Ar-OH)
Examples:
Example 1
A 0 C solution of conc. H2SO4 (10 mL) in H2O (38 mL) was added to the SM (2.52 g, 11.5 mmol) at 0 C. Approximately 20 min later, a solution of NaNO2 (0.800 g, 11.6 mmol) in H2O (13 mL) was added dropwise over a span of 35 min. After 40 min at 0 C, the mixture was warmed to RT and stirred for an additional 90 min. Then was added H2O (40 mL), and the resulting solution was stirred at reflux for about 2 h. The mixture was cooled to RT, saturated with NaCl, and extracted with EtOAc (4x). The combined organics were dried (Na2SO4) and concentrated to give a thick oil. The crude material was purified by silica gel flash chromatography to provide the product as a pale yellow solid. [1.63 g]
[Patent Reference: WO2016014463, page 138, 
(6.7 MB)]