Application of 28643-16-5,Some common heterocyclic compound, 28643-16-5, name is Methyl 3-amino-5-chloropyrazine-2-carboxylate, molecular formula is C6H6ClN3O2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
a) 3-Amino-5-((Z)-2-ethoxy-vinyl)-pyrazine-2-carboxylic acid methyl ester A mixture of 3-amino-5-chloro-pyrazine-2-carboxylic acid methyl ester [28643-16-5] (2 g, 10.66 mmol), lithium chloride (1.582 g, 37.3 mmol), Pd(PPh3)2CI2 (0.748 g, 1.066 mmol) and tributyl- ((Z)-2-ethoxy-vinyl)-stannane (6.42 ml, 19.19 mmol) in DMF (104 ml) under argon was heated at 80 C bath temperature for 1.5 h. A saturated, aq. NH4CI was added and the mixture was extracted with MTBE, then once with EtOAc/THF 3/1. The combined organic layer was washed with brine, dried with Na2S04, filtered and concentrated under reduced pressure. The residue was purified by chromatography on silica gel (cyclohexane to cyclohexane/EtOAc 1 :9) to provide the title compound as yellow oil (1.96 g). HPLC: RtH2= 0.69 min; ESIMS [M+H]+ = 225.1 ; 1H-NMR (400 MHz, DMSO-c 6): delta 8.42 (s, 1 H), 7.18 (br. s, 2H), 6.88 (d, 1 H), 5.23 (d, 1 H), 4.15 (q, 2H), 3.82 (s, 3H), 1.32 (t, 3H).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 3-amino-5-chloropyrazine-2-carboxylate, its application will become more common.
Reference:
Patent; NOVARTIS AG; LUEOEND, Rainer Martin; MACHAUER, Rainer; RUEEGER, Heinrich; VEENSTRA, Siem Jacob; WO2013/27188; (2013); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem