Imidazole → 7-(4-Fluoro-benzyl)-5-hydroxy-9-triisopropylsilanyloxy-pyrrolo[3,4-g]quinoline-6,8-dione

Participants

Reaction Steps

A solution of 7-(4-fluoro-benzyl)-5,9-dihydroxy-pyrrolo[3,4-g]quinoline-6,8-dione 2 (1.039 g, 3.07 mmol) in 31 mL of DMF was stirred with imidazole (314 mg, 4.62 mmol) and triisopropylsilylchloride (TIPSCl, 0.723 mL, 3.38 mmol) under a N2 atmosphere for 1.5 days when most of the starting materials was converted to the regiospecific mono TIPS (triisopropylsilyl) protected compound. The solid bisphenol left in the reaction was filtered and recycled. The mother liquor was dried and the residue was suspended in EtOAc. The organic layer was washed with water and dried. The resulted solid 12 was carried to the next step. EI MS (m/z) 495.6 [MH+], 517.4 [M+Na].

Provenance & Evidence