반응 #5218

반응 방정식

trifluoroacetic acid

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

triethylsilane

methanol

NaHCO3

→

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

용매

ether

반응 조건

후처리

1. 1
   추출The aqueous layer was extracted with ether (10 mL)
2. 2
   세척the combined ether layers were washed with water (10 mL) and brine (10 mL)
3. 3
   건조dried (Na2SO4)
4. 4
   농축Concentration
5. 5
   기타gave the crude product which
6. 6
   기타was purified by radial PLC (silica gel, 5% ethyl acetate/hexanes)

실험 절차

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.

출처