Triethylamine → ethyl 6-iodo-2-trifluoromethyl-2H-1-benzopyran-3-carboxylate

HRID 393313Notes

Reaction equation

HRID 393313 reaction equation
[I:1][C:2]1[CH:9]=[C:6]([CH:7]=O)[C:5]([OH:10])=[CH:4][CH:3]=1.[F:11][C:12]([F:21])([F:20])/[CH:13]=[CH:14]/[C:15]([O:17][CH2:18][CH3:19])=[O:16].C(N(CC)CC)C>C(OCC)(=O)C>[I:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH:13]([C:12]([F:11])([F:21])[F:20])[C:14]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:7][C:6]=2[CH:9]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 2526125-IodosalicylaldehydeHCID 5371261Ethyl (2E)-4,4,4-trifluoro-2-butenoate

Product 1

HCID 21883584ethyl 6-iodo-2-trifluoromethyl-2H-1-benzopyran-3-carboxylateYield 31.9%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
70 °C

Procedure

A mixture of 5-iodosalicylaldehyde (16.2 g, 65.3 mmol), ethyl 4,4,4-trifluorocrotonate (22.4 g, 133 mmol) and triethylamine (50 ml, 395 mmol)were combined, stirred at 70° C. for 8 h and then heated at reflux for 48 h. The solution was poured into ethyl acetate (300 mL) and washed with 1N hydrochloric acid (3×200 mL). The aqueous layers were combined and extracted with ethyl acetate (1×100 mL). The combined ethyl acetate extracts were washed with saturated ammonium chloride (2×200 mL), dried over magnesium sulfate and concentrated in vacuo yielding a dark red oil. This oil was purified by flash chromatography using ethyl acetate-hexanes (3:7) yielding a red oil. Crystallization of this oil from hexanes yielded the title compound as light red crystals (8.3 g, 31%): mp 105-106° C. 1H NMR (CDCl3/300 MHz) 7.63 (s, 1H), 7.58 (dd, 2H, J=8.6, J=2.1 Hz, 7.54 (d, 1H, J=2.1 Hz), 6.77 (d, 1H, J=8.6 Hz), 5.70 (q, 1H, J=6.7 Hz), 4.20-4.38 (m 2H), 1.35 (t, 3H, J=7.2 Hz). ESHRMS 415.9926 (M+NH4+ Calc'd 396.9746).

Workup

  1. temperatureheated
  2. temperatureat reflux for 48 h
  3. washwashed with 1N hydrochloric acid (3×200 mL)
  4. extractionextracted with ethyl acetate (1×100 mL)
  5. washThe combined ethyl acetate extracts were washed with saturated ammonium chloride (2×200 mL)
  6. dry with materialdried over magnesium sulfate
  7. concentrationconcentrated in vacuo
  8. customyielding a dark red oil
  9. customThis oil was purified by flash chromatography
  10. customyielding a red oil
  11. customCrystallization of this oil from hexanes

Sources & evidence

ORD record
ord-366b8e855ffd4840b1503a112e1df1e7
Source dataset
uspto-grants-2004_10
Patent number
US06806288B1

Reaction notes

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