Acetic Acid → 2-(2,6-Dimethylphenyl)-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine

Beteiligte Stoffe

Reaktionsschritte

To a solution of 6-benzyl-2-(2,6-dimethylphenyl)-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (7.08 g, 19.70 mmol) in THF (100 mL) and H2O (12.50 mL), was added 20% Pd(OH)2 wet (50% dry basis, 2.77 g, 1.970 mmol), followed by acetic acid (2.26 mL, 39.4 mmol). The reaction was stirred at r.t. under hydrogen atmosphere for 30 min, then heated to 40° C. for 16 h. The reaction mixture was cooled to r.t. and filtered through a Celite® pad which was washed with methanol. The organic solvent in the filtrate was removed under reduced pressure. The reaction mixture was diluted by 200 mL DCM and neutralized by saturated aqueous NaHCO3. The mixture was extracted twice by DCM. The combined organic layers were dried over Na2SO4. After filtration and concentration, the resulting residue was purified via silica gel FCC (Methanol/DCM=0 to 10%) to provide 2-(2,6-dimethylphenyl)-4-methoxy-5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.14-7.22 (m, 1 H), 7.05-7.11 (m, 2 H), 5.75 (s, 1 H), 3.88 (s, 3 H), 3.72 (s, 2 H), 3.01 (t, J=5.8 Hz, 2 H), 2.68 (t, J=5.7 Hz, 2 H), 2.03 (s, 6 H). MS (ESI+) m/z 270.5 (M+H)+.

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