Yield: 44%

Reaction Conditions:

with diiodomethane;isopentyl nitrite in diiodomethane at 85 - 100; for 15 h;

Steps:

15 3-Iodopyrazine-2-carboxylic acid methyl ester (Reference compound No.15-1)
Reference Example 15 3-Iodopyrazine-2-carboxylic acid methyl ester (Reference compound No.15-1) Isoamyl nitrite (5.2 mL, 39 mmol) was added to a suspension of 3-aminopyrazine-2-carboxylic acid methyl ester (1.9 g, 12 mmol) in diiodomethane (20 mL) at 85°C, then the mixture was stirred at 100°C for 15 hours. The reaction mixture was allowed to stand and purified by silica gel column chromatography to give 1.4 g of the title reference compound as a pale yellow solid. (Yield 44%) ¹H-NMR(500MHz,CDCl₃) δ 4.04(s,3H),8.47(d,J = 2.1 Hz,1H),8.56(d,J = 2.1 Hz,1H)

References:

SANTEN PHARMACEUTICAL CO., LTD. EP1602647, 2005, A1 Location in patent:Page/Page column 58