4-Pyridinamine,3-bromo-N-methyl-(9CI) synthesis

Yield:84539-38-8 30%

Reaction Conditions:

with lithium aluminium tetrahydride in tetrahydrofuran at 0;Reflux;

Steps:

3-Bromo-N-methylpyridin-4-amine (S8).

Ethyl (3-bromopyridin-4-yl)carbamate S7 (100 mol%) in THF (0.5 M) was added to a slurry ofLiAlH₄ (150 mol%) in THF (0.5 M) at -78 °C. The mixture was stirred at 0 °C for 30 min,warmed to ambient temperature, and heated to reflux for additional 2-3 h. After completion, the mixture was cooled to 0 °C, diluted with CH₂Cl₂, and saturated acquous solution of Rochelle’ssalt. The pH was adjusted with acetic acid to 7. The organic layer was washed with water, brine.The combined aqueous layer was washed with CH₂Cl₂. The combined organic layer was driedover anhydrous Na₂SO₄, concentrated in vacuo. The product S8 was obtained as a yellow oil in 30% yield (233.1 mg, 1.54 mmol) after flash column chromatography (CHCl₃/MeOH = 9:1). ¹H NMR (400 MHz, CDCl₃) δ 8.35 (d, J = 5.0 Hz, 1H), 8.17 (d, J = 5.5 Hz, 1H), 6.47 (t, J = 5.6Hz, 1H), 4.92 (s, 1H), 2.93 (m, 3H). ¹³C NMR (100 MHz, CDCl3) δ 151.1, 149.7, 148.4, 107.3, 105.4, 29.6. IR (neat) 3247, 2915, 2361, 1588, 1517, 1191, 1010 cm^-1. HRMS (ESI+) calcd. for C₆H₈BrN₂ [M+H]+ 186.9865, found 186.9860

References:

Shin, Inji;Ramgren, Stephen D.;Krische, Michael J. [Tetrahedron,2015,vol. 71,# 35,art. no. 26803,p. 5776 - 5780] Location in patent:supporting information