Trifluoroacetic acid → HCID 136104957, compound

Participants

Reaction Steps

tert-Butyl-1-(2-(2-hydroxyphenyl)-7-methylquinazolin-4-yl)piperidin-4-ylcarbamate (55.7 g, 128 mmol) was dissolved in dichloromethane (200 mL) and trifluoroacetic acid (215 ml) was slowly added (careful: immediate gas evolution!). The resulting solution was stirred overnight at room temperature under a nitrogen atmosphere and evaporated to dryness. To the residue were added equal amounts of water and dichloromethane (300 mL). The obtained emulsion was basified to pH 9 with 33% aq. NaOH. The emulsion was cleared by the addition of methanol, and the layers were separated. The aqueous layer was extracted with dichloromethane (200 mL), and the combined organic extracts were dried over sodium sulfate, filtered, and evaporated to dryness to yield crude 2-(4-(4-aminopiperidin-1-yl)-7-methylquinazolin-2-yl)phenol. The crude material was purified by column chromatography (SiO2, 2% methanol in dichloromethane) to yield 2-(4-(4-aminopiperidin-1-yl)-7-methylquinazolin-2-yl)phenol (44 g, 97%) as a yellow solid. 1H-NMR (300 MHz, CDCl3): δ 8.52 (dd, J=2.1, 8.1 Hz, 1H), 7.77 (d, J=8.4 Hz, 1H), 7.62 (s, 1H), 7.37 (dt, J=1.5, 7.2 Hz, 1H), 7.22 (dd, J=1.5, 9.0 Hz, 1H), 7.04 (dd, J=1.2, 6.9 Hz, 1H), 6.92 (dt, J=1.2, 7.2 Hz, 1H), 4.49-4.39 (m, 2H), 3.34 (dt, J=2.4, 12.2 Hz, 2H), 3.12-3.02 (m, 1H), 2.54 (s, 3H), 2.09-2.00 (m, 2H), 1.68-1.55 (m, 2H), 1.40-1.25 (m, 2H) ppm.

Provenance & Evidence