HCID 18696600, compound → HCID 18696622, compound

Participants

Reaction Steps

A solution of the title compound of Step E (4.6 g) in methylene chloride (40 mL) under nitrogen was cooled to -78° C. while stirring. A solution of diisobutylaluminum hydride (55.0 mL, 1 M in CH2Cl2) in methylene chloride was then added, the reaction mixture was allowed to warm to room temperature and stirred for 1 h. The reaction was monitored by TLC (5% methanol/ethyl acetate). After cooling back down to -78° C., the reaction was diluted with acetone (45 mL), quenched with glacial acetic acid (20 mL) and then allowed to warm to room temperature. The resulting mixture was further diluted with water (200 mL) and extracted successively with methylene chloride and ethyl acetate. The combined organic extracts were dried (MgSO4), filtered and concentrated under reduced pressure to yield 3.62 g of the title compound of Step F as an orange solid melting at 132.5-133.5° C. 1H NMR (CDC3): δ 7.53 (s,2H), 4.38 (s,3H), 3.99 (s,3H), 3.44 (s,3H).

Provenance & Evidence