Boronic acid, B-(2-formyl-3-methoxyphenyl)-

Conditions: temp:2.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of t-butyl lithium (9.0 mL, 1.7 M in pentane) was added to a stirred solution of 2-(2-methoxyphenyl)-1,3-dimethylimidazolidine (2.0 g, 9.8 mmol) in THF (5 mL) at −10° C. under N2 and stirred at 0-5° C. for 2 hours. The reaction mixture was cooled to −50° C. and triisopropylborate (3.5 mL, 15 mmol) was added. The solution was slowly warmed to 0° C. in 3 hrs. HCl (120 mL of 2N) was added at 0° C. and let it stirred for 30 min. The mixture was warmed to room temperature and was diluted with ethyl acetate. The organic layer was washed ( 2× HCl (1 N), brine), dried ( sodium sulfate) and concentrated to afford yellow crude product which purified by reverse phase HPLC chromatography. Upon removal of solvent 3-methoxy-2-formylphenylboronic acid crystallized as a light yellow solid, 1.3 g (yield 75%). ESI-MS m/e 177 (MH+). The reaction mixture was cooled to −50° C. The solution was slowly warmed to 0° C. in 3 hrs stirred for 30 min The mixture was warmed to room temperature The organic layer was washed ( 2× HCl (1 N), brine) dried ( sodium sulfate) concentrated to afford yellow crude product which purified by reverse phase HPLC chromatography Upon removal of solvent 3-methoxy-2-formylphenylboronic acid crystallized as a light yellow solid, 1.3 g (yield 75%)