3,5-dichloro-2-iodopyrazine

Synthesis of 3, 5-dlchloro-2-iodopyrazine (11a): 2, 6-Dichloropyrazine (9) (149 mg, 1.0 mmol) in THF (2 mL) was added to a solution of TMPZnCl.LiCl (2) (1.3 M in THF, 0.85 mL, 1.1 mmol) at 25° C. and the reaction mixture was then stirred at this temperature for 30 min according to TP 2. IGeneral procedure: [Li(TMP)Zn(tBu)A round-bottom flask was charged with Preparation Example 372 A mixture of Synthesis of 3, 5-dlchloro-2-iodopyrazine (11a): 2, 6-Dichloropyrazine (9) (149 mg, 1.0 mmol) in THF (2 mL) was added to a solution of TMPZnCl.LiCl (2) (1.3 M in THF, 0.85 mL, 1.1 mmol) at 25 C. and the reaction mixture was then stirred at this temperature for 30 min according to TP 2. I2 (381 mg, 1.5 mmol) dissolved in dry THF (2 mL) was then dropwise added and the resulting mixture was stirred for 0.5 h. The reaction mixture was quenched with a sat. aq. Na2S2O3 solution (10 mL) and with a sat. aq. NH4Cl solution (20 mL), extracted with diethyl ether (3×50 mL) and driedanhydrous Na2SO4. After filtration, the solvent was evaporated in vacuo. Purification by flash-chromatography (CH2Cl2/n-pentane, 1:2) furnished compound 11a (251 mg, 90%) as a colourless solid.m.p.: 101.3-103.0 C.1H-NMR (300 MHz, CDCl3) delta: 8.30 (s, 1 H).13C-NMR (75 MHz, CDCl3) delta: 153.1, 146.9, 142.4, 115.7.MS (70 eV, El) m/z (%): 274 (100) [M+], 147 (75), 127 (18), 86 (32), 57 (21), 44 (94). IR (ATR) v (cm-1): 2969, 2633, 2281, 1784, 1738, 1510, 1491, 1379, 1353, 1323, 1274, 1230, 1217, 1205, 1175, 1162, 1143, 1018, 893, 843, 655, 634, 618, 611, 604.HRMS (El) for C4HCl2IN2 (273.8561): 273.8555.General procedure: [Li(TMP)Zn(tBu)2] 1 was made according to the literature procedure2 on a 0.4 mmol scale in THF solution. To this solution 2-methoxypyridine (0.042 mL, 0.4 mmol) was added and the resultant light orange reaction allowed to stir at room temperature for 2 hours. Next the solution was cooled to 0C and quenched with I2 (508 mg, in 1 mL THF) and allowed to stir for 1 hour. Next a 10% solution of Na2S2O3 was added until bleaching and the product extracted with DCM (3 x 1 mL). The combined organic extracts were dried over MgSO4 and the solvent removed under reduced pressure. The residue was purified by SiO2 chromatography using Heptane:DCM as eluent (20:80-->40:60) to give 3-iodo2-methoxypyridine 2a as a colourless oil (87.1 mg, 92% yield).

Molecular Weight:274.87
XLogP3:2.4
Hydrogen Bond Acceptor Count:2
Exact Mass:273.85615
Monoisotopic Mass:273.85615
Topological Polar Surface Area:25.8
Heavy Atom Count:9
Complexity:103
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes