6-Bromo-4-methyl-3,4-dihydro-2H-1,4-benzoxazine synthesis

9synthesis methods

Product Name:6-Bromo-4-methyl-3,4-dihydro-2H-1,4-benzoxazine
CAS Number:188947-79-7
Molecular formula:C9H10BrNO
Molecular Weight:228.09

6-Bromo-3,4-dihydro-2H-benzo[1,4]oxazine hydrochloride

105655-01-4
122 suppliers
$27.00/250mg

74-88-4
342 suppliers
$15.00/10g

6-Bromo-4-methyl-3,4-dihydro-2H-1,4-benzoxazine

188947-79-7
28 suppliers
$65.00/25mg

Yield:188947-79-7 87%

Reaction Conditions:

with potassium carbonate in acetonitrile at 50;Inert atmosphere;

Steps:

1 [Synthesis of Compound E5]

[Synthesis of Compound E5] (0136) Compound E4 (1.90 g, 8.88 mmol, 1 Eq) was dissolved in acetonitrile (20 mL) in an argon atmosphere, and potassium carbonate (1.98 g, 14.3 mmol, 1.6 Eq) and methyl iodide (3.0 mL, 47.5 mmol, 5 Eq) were added and the combination was stirred overnight at 50° C. After returning the reaction system to room temperature and distilling off the solvent under reduced pressure, the reaction system was diluted by ethyl acetate, the insoluble matter was distilled off by filtration under reduced pressure, and the filtrate was removed under reduced pressure. The residue obtained was purified by medium-pressure silica gel chromatography (eluent: n-hexane/ethyl acetate=98/2 to 90/10), and the target compound E5 (1.77 g, 87%) was obtained as a pale yellow solid. (0137) ¹H NMR (CDCl₃): δ 6.73-6.70 (m, 2H), 6.61 (d, J=8.0 Hz, 1H), 4.25 (t, J=4.4 Hz, 2H), 3.26 (t, J=4.4 Hz, 2H), 2.86 (s, 3H).; ¹³C NMR (CDCl₃): δ 143.3 (C), 137.9 (C), 120.5 (CH), 117.2 (CH), 114.9 (CH), 113.8 (C), 64.8 (CH₂), 48.8 (CH₂), 38.7 (CH₃).; HRMS-ESI (m/z): [M+H]⁺ calcd for C₉H₁₁BrNO: 228.00185. found: 228.00185. found: 228.00168 (0.2 mDa, 0.8 ppm).