Dimethyl Sulfoxide → 4-{6-Methoxy-7-[3-(4-methyl-piperazin-1-yl)-propoxy]-quinazolin-4-yl}-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

A mixture of 4-{6-Fluoro-7-[3-(4-methyl-piperazin-1-yl)-propoxy]-quinazolin-4-yl}-piperidine-1-carboxylic acid tert-butyl ester (32.6 mg, 66.9 μmol), as prepared in Example 205d, DMSO (50 μL), and 0.31M KOMe/MeOH (270 μL, 83.9 μmol KOMe in 6.4 mmol MeOH) was stirred at 100° C. for 9 hr, and then 110° C. for 2 hr. The resulting pale yellow homogeneous solution was allowed to cool to rt, diluted with DCM (2 mL), and washed with 4M NaCl (1×2 mL). The aq layer was back-extracted with DCM (1×2 mL), and the combined organic layers were dried (Na2SO4) and concentrated. Purification of the residue by silica flash chromatography (1:2 hex/EtOAc→1:2 hex/EtOAc/3% DMEA→9:1 EtOAc/acetone/3% DMEA eluent) afforded the title compound (18.4 mg, 55%). NOe experiments support the assigned regioisomer. Select 1H-NMR resonances and nOes (300 MHz, CDCl3) δ 7.34 (s, 1H), 7.24 (s, 1H), 4.04 (s, 3H), 3.51 (m, 1H). Irradiation of the diagnostic methine proton at δ 3.51 generates an nOe to the quinazoline C5 proton at δ 7.24, but not to the quinazoline C8 proton at δ 7.34. Irradiation of the methoxy protons at δ 4.04 generates an nOe to the C5 proton at δ 7.24, but not to the C8 proton at δ 7.34. This indicates methoxy substitution at C6 of the quinazoline. LC/MS (ESI): calcd mass 499.3, found 500.4 (MH)+.

Provenance & Evidence