Methanol → 2-Chloro-4-iodo-6-methoxy-5-(methoxymethyl)pyridine

HRID 256716Notes

Reaction equation

HRID 256716 reaction equation
[Cl:1][C:2]1[N:7]=[C:6]([O:8][CH3:9])[C:5]([CH:10]=[O:11])=[C:4]([I:12])[CH:3]=1.[CH2:13]([SiH](CC)CC)C.CO.FC(F)(F)C(O)=O.C([O-])(O)=O.[Na+]>CCOCC>[Cl:1][C:2]1[CH:3]=[C:4]([I:12])[C:5]([CH2:10][O:11][CH3:13])=[C:6]([O:8][CH3:9])[N:7]=1

Participants

7

Conditions

Temperature
25 °C

Procedure

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.

Workup

  1. extractionThe aqueous layer was extracted with ether (10 mL)
  2. washthe combined ether layers were washed with water (10 mL) and brine (10 mL)
  3. dry with materialdried (Na2SO4)
  4. concentrationConcentration
  5. customgave the crude product which
  6. customwas purified by radial PLC (silica gel, 5% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-d1770a3f567e4b10b98bd2a3afb82831
Source dataset
uspto-grants-1993_11
Patent number
US05258516

Reaction notes

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