تفاعل #5218

معادلة التفاعل

trifluoroacetic acid

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

triethylsilane

methanol

NaHCO3

→

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

المذيبات

ether

ظروف التفاعل

المعالجة

1. 1
   استخلاصThe aqueous layer was extracted with ether (10 mL)
2. 2
   غسيلthe combined ether layers were washed with water (10 mL) and brine (10 mL)
3. 3
   تجفيفdried (Na2SO4)
4. 4
   تركيزConcentration
5. 5
   أخرىgave the crude product which
6. 6
   أخرىwas purified by radial PLC (silica gel, 5% ethyl acetate/hexanes)

الإجراء التجريبي

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.

المصدر