ethyl 5-methylpyrazine-2-carboxylate synthesis
- Product Name:ethyl 5-methylpyrazine-2-carboxylate
- CAS Number:41110-34-3
- Molecular formula:C8H10N2O2
- Molecular Weight:166.18
5521-55-1
64-17-5
41110-34-3
5-Methylpyrazine-2-carboxylic acid (300.84 g), AMBERLYST 15 ion-exchange resin (60.17 g) and ethanol (1004 g) were added to a 2L four-necked flask equipped with a mechanical stirrer, a water condenser (with a gas inlet), and a thermocouple under nitrogen atmosphere. The reaction mixture was stirred under reflux conditions for about 16 h. The reaction progress was confirmed by GC or GC/MS monitoring. Upon completion of the reaction, the resin was removed by pressurized filtration and the resin was washed with ethanol. The washings were combined into an ethanol solution of the ester. Subsequently, the solvent was removed by distillation under reduced pressure to afford 336.7 g (93% yield) of ethyl 5-methylpyrazine-2-carboxylate, which can be used directly in subsequent experiments. In addition, the product could be further purified by a thin film evaporator at 125 °C/3 mmHg, the product obtained by distillation was almost colorless and crystallized at about 20 °C.
5521-55-1
458 suppliers
$9.00/5g
64-17-5
758 suppliers
$10.00/50g
41110-34-3
55 suppliers
$128.00/10g
Yield:41110-34-3 93%
Reaction Conditions:
with AMBERLYST 15 ion exchange resin for 16 h;Heating / reflux;
Steps:
3 EXAMPLE 3
The reaction was carried out, under nitrogen, in a 2 L×4 neck flask equipped with a mechanical stirrer, water condenser (with gas inlet), and a thermocouple. The reactor was charged with 5-methylpyrazinecarboxylic acid (300.84 g), AMBERLYST 15 ion exchange resin (60.17 g), and ethanol (1004 g). The mixture was stirred at reflux for about 16 h after which the reaction was found to be complete by GC or GC/MS. The resin was removed by pressure filtration and rinsed with ethanol. The rinse was added to the alcohol solution of the ester. Evaporation of the solvent under reduced pressure gave 336.7 g (93%) of 5-methylpyrazinecarboxylic acid, ethyl ester that was suitable for use in the following examples. It was also possible to pass the material through a thin film evaporator at 125° C./3 mm. The material from this distillation was almost colorless and crystallizes at about 20° C.
References:
US2005/261312,2005,A1 Location in patent:Page/Page column 2