N-Methyl Carvedilol (Carvedilol impurity) synthesis
- Product Name:N-Methyl Carvedilol (Carvedilol impurity)
- CAS Number:72956-35-5
- Molecular formula:C25H28N2O4
- Molecular Weight:420.51
Yield:72956-35-5 54%
Reaction Conditions:
Stage #1: carvedilolwith sodium hydride in tetrahydrofuran at 0; for 0.333333 h;
Stage #2: methyl iodide in tetrahydrofuran at 0 - 20; for 4 h;
Steps:
7
Preparation of 8a and 11a (FIG. 13, Scheme 5):; A suspension of NaH (60% in oil) (10 mg, 0.25 mmol) in anhydrous THF was cooled to 0° C. Then a solution of carvedilol 1a (100 mg, 0.246 mmol) in THF was added and the mixture was stirred for 20 min at the same temperature. Methyl iodide (35 mg, 0.25 mmol) was added and stirring was continued for 4 h at room temperature. The reaction mixture was quenched with water (10 mL) and extracted with ethyl acetate (3×10 mL). The organic layer washed with saturated NH4Cl solution (25 mL), dried over Na2SO4, evaporated under reduced pressure and the residue was purified by flash chromatography over silica gel to afford 8a: yield: 54%; viscous oil; 1H NMR (300 MHz) δ 8.29-8.20 (m, 2H), 7.41-7.31 (m, 3H), 7.28-7.26 m, 1H), 7.06 (d, J=8.1 Hz, 1H), 6.93-6.87 (m, 4H), 6.66 (d, J=8.1 Hz, 1H), 4.36-4.21 (m, 5H), 3.78 (s, 3H), 3.27-3.13 (m, 4H), 2.72 (s, 3H); 13C NMR (75 MHz) δ 154.94, 149.71, 147.63, 140.97, 138.75, 126.70, 125.00, 122.87, 122.47, 122.11, 120.91, 119.65, 114.32, 112.68, 111.91, 110.09, 103.99, 101.25, 69.88, 66.11, 66.04, 61.18, 56.39, 55.71, 43.04; mass spectrum, m/z 420 (M+). Exact mass calcd for C25H28N2O4: 420.20491. Found: 420.20380.
References:
US2007/254849,2007,A1 Location in patent:Page/Page column 18
51997-51-4
315 suppliers
$7.00/5g
72956-35-5
24 suppliers
inquiry
1836-62-0
317 suppliers
$6.00/10g
72956-35-5
24 suppliers
inquiry