Electric Literature of 21279-64-1, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 21279-64-1 name is 5-Chloropyrazine-2-carboxamide, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
5-[18F]F-PZA was synthesized via a halogen exchange reaction, similar to the method used tosynthesize 5-F-PZA (Fig 2). 2960 MBq (80 mCi) of aqueous [18F]fluoride in ddH2O was purchasedfrom PETNET Solutions Inc. The [18F]fluoride was placed in a vial containing Kryptofix2.2.2 (5 mg, 13 mumol) and potassium carbonate (1 mg, 7 mumol) and the solution was thendried by azeotropic distillation. The solid residue was then re-solubilized with 0.2±0.3 mL ofacetonitrile containing 1±2 mg 5-chloropyrazinamide (5-Cl-PZA). The reaction mixture washeated in a securely capped 2 mL reaction vial at 105C for 8 min, and subsequently quenchedwith 0.8 mL water. The reaction mixture was filtered through a vented 0.22 um Millipore filterusing a 1 mL syringe and then purified by HPLC with an isocratic mobile phase of 8% acetonitrile/92% 0.02Maqueous ammonium acetate with 5% acetic acid (Phenomenex Luna PFP,250 × 10, 5 mum, 4 mL/min). The radioactive product eluted at the same retention time as the5-F-PZA standard (10 to 12 min). The solvent was removed by rotary evaporation. The residuewas re-solubilized in sterile phosphate buffered saline and the pH of the solution was adjustedto 7.4 by the addition of 2M NaOH. The solution was filtered through an Acrodisc 13 mmsyringe filter equipped with a 0.2 mum Supor membrane (Pall Corporation) into a sterile vial.Radiochemical purity was determined by reverse-phase analytical HPLC (Phenomenex PFP,250 × 4.6, 5 mum, 1 mL/min, 8% acetonitrile/92% 0.02Maqueous ammonium acetate with 5%acetic acid mobile phase).
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 5-Chloropyrazine-2-carboxamide, and friends who are interested can also refer to it.
Reference:
Article; Zhang, Zhuo; Ordonez, Alvaro A.; Smith-Jones, Peter; Wang, Hui; Gogarty, Kayla R.; Daryaee, Fereidoon; Bambarger, Lauren E.; Chang, Yong S.; Jain, Sanjay K.; Tonge, Peter J.; PLoS ONE; vol. 12; 2; (2017);,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem