methyl 3,6-dibromopyrazine-2-carboxylate synthesis
- Product Name:methyl 3,6-dibromopyrazine-2-carboxylate
- CAS Number:13301-04-7
- Molecular formula:C6H4Br2N2O2
- Molecular Weight:295.92
6966-01-4
223 suppliers
$8.00/1g
13301-04-7
148 suppliers
$7.00/250mg
Yield:13301-04-7 49%
Reaction Conditions:
Stage #1:methyl 3-amino-6-bromopyrazine-2-carboxylate with hydrogen bromide;bromine;acetic acid in water at 0; for 0.75 h;
Stage #2: with sodium nitrite in water at 0; for 0.5 h;Product distribution / selectivity;
Steps:
58.2
Step 2; A suspension of compound 2 (28.5 g, 120 mmol) in an aqueous solution of 48% HBr (120 mL) and acetic acid (30 mL) was cooled to 0° C., and then treated with a solution of bromine (18 mL, 336 mmol) in acetic acid (18 mL) over a period of 45 min. A solution of NaNO2 (8.28 g, 420 mmol) in water (15 ml) was added while maintaining the temperature at 0° C., stirring was continued for further 30 min. After completion of reaction (reaction progress was monitored by TLC), the excess bromine was quenched by the drop wise addition of 30% aqueous solution of NaHSO3 (180 mL). The resulting precipitate was filtered and purified by column chromatography on silica gel eluted with 10% ethyl acetate in hexane to afford compound 3 as a white crystalline solid (18 g, 49%). MS m/z (ES): 294 (M+H)+.
References:
de Vicente Fidalgo, Javier;Hermann, Johannes Cornelius;Lemoine, Remy;Li, Hongju;Lovey, Allen John;Sjogren, Eric Brian;Soth, Michael US2011/59118, 2011, A1 Location in patent:Page/Page column 84-85
16298-03-6
333 suppliers
$7.00/1g
13301-04-7
148 suppliers
$7.00/250mg
5424-01-1
346 suppliers
$10.00/5g
13301-04-7
148 suppliers
$7.00/250mg