ChemicalBook CAS DataBase List Iodopyrazine

Iodopyrazine synthesis

5synthesis methods

Product Name:Iodopyrazine
CAS Number:32111-21-0
Molecular formula:C4H3IN2
Molecular Weight:205.98

14508-49-7 Synthesis

14508-49-7
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32111-21-0
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$7.00/1g

Yield:32111-21-0 60%

Reaction Conditions:

Stage #1:2-chloropyrazin with acetic acid;sodium iodide;sulfuric acid in acetonitrile for 4.5 h;Reflux;
Stage #2: with sodium hydrogencarbonate in water

Steps:

1
A reaction mixture of chloropyrazine (7.5 ml, 83 mmol), NaI (30.3 g, 202 15 mmol), HOAc (9.6 ml, 168 mmol) and H₂SO₄ (0.5 ml) in MeCN (105 ml) was heated at reflux for 4.5 hours. The solvent was removed and water (120 ml) was added. After the solution was basified with saturated NaHCO₃, it was extracted with dichloromethane (DCM) (2 x 125 ml). The DCM layers were combined, washed with saturated Na₂S₂O₃, brine and dried. The removal of solvent gave crude iodopyrazine as an oil (12.33 g, 20 71%). Analysis by ¹H NMR showed there was less than about 10 mol% of chloropyrazine in the oil. Another batch of chloropyrazine (50 g, 437 mmol) was also converted into crude iodopyrazine (about 65 g) by the same procedure. These two batches of crude iodopyrazine were combined and distillation of the crude iodopyrazine under reduced pressure (about 0.75 torr, bp 47°C) gave pure compound 64 g (60%). 25¹H-NMR (CDCl₃, 300MHz) 8.40 (dd, /=1.8, 2.4Hz, IH), 8.51 (d, /=2.4Hz,lH), 8.87 (d, /=1.5Hz,lH).

References:

INTERNATIONAL PARTNERSHIP FOR MICROBICIDES WO2009/114313, 2009, A2 Location in patent:Page/Page column 15

FullText

290-37-9 Synthesis