反応 #5218

反応方程式

trifluoroacetic acid

6-chloro-4-iodo-2-methoxy-3-pyridinecarboxaldehyde

triethylsilane

methanol

NaHCO3

→

2-chloro-4-iodo-6-methoxy-5-(methoxymethyl)pyridine

溶媒

ether

反応条件

後処理

1. 1
   抽出The aqueous layer was extracted with ether (10 mL)
2. 2
   洗浄the combined ether layers were washed with water (10 mL) and brine (10 mL)
3. 3
   乾燥dried (Na2SO4)
4. 4
   濃縮Concentration
5. 5
   その他gave the crude product which
6. 6
   その他was purified by radial PLC (silica gel, 5% ethyl acetate/hexanes)

実験手順

To a mixture of 6-chloro-4-iodo-2-methoxy-3-pyridinecarboxaldehyde (1.07 g, 3.60 mmol), triethylsilane (0.86 mL, 5.40 mmol) and methanol (0.43 mL, 10.6 mmol) at 0° C. was added trifluoroacetic acid (2.2 mL, 28.6 mmol), and the resulting solution was stirred at 25° C. for 14 h. After dilution with ether (30 mL), saturated NaHCO3 was added until the aqueous phase was rendered basic. The aqueous layer was extracted with ether (10 mL), and the combined ether layers were washed with water (10 mL) and brine (10 mL), and dried (Na2SO4). Concentration gave the crude product which was purified by radial PLC (silica gel, 5% ethyl acetate/hexanes) to afford 2-chloro-4-iodo-6-methoxy-5-(methoxymethyl)pyridine as a white solid (1.05 g., 93%): mp 69°-72° C. Recrystallization from hexanes provided an analytical sample: mp 74°-75° C. 1H NMR (300 MHz, CDCl3) δ 7.40 (S, 1H), 4.53 (s, 2H), 3.96 (s, 3H), 3.42 (s, 3H); IR (nujol) 1550, 1300, 1115, 1090, 1020, 940, 905, 830, 720 cm-1.

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