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

HRID 1612924Notes

Reaction equation

HRID 1612924 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, 1 H), 4.53 (s, 2 H), 3.96 (s, 3 H), 3.42 (s, 3 H); 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-1465ca9421a944708e732ba01a588f5b
Source dataset
uspto-grants-1993_03
Patent number
US05191082

Reaction notes

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