반응 #155422

반응 방정식

4-hydroxybenzaldehyde

tetrahydro-pyran-4-carboxylic acid

thionyl chloride

pyridine

→

4-formylphenyl tetrahydro-2H-pyran-4-carboxylate

수율 87.4%

용매

water

CH2Cl2

반응 조건

후처리

1. 1
   기타To a 100 mL dry round bottom flask
2. 2
   온도The mixture was refluxed for 45 minutes
3. 3
   기타all the volatile materials were rotary-evaporated
4. 4
   workup.ADDITIONTo the residue, anhydrous CH2Cl2 (10 mL) was added
5. 5
   온도warmed from 0° C. to room temperature slowly
6. 6
   기타at room temperature
7. 7
   기타overnight
8. 8
   기타the CH2Cl2 layer was separated
9. 9
   추출The aqueous layer was extracted continually with CH2Cl2 (50 mL×3)
10. 10
    세척The combined CH2Cl2 solution was washed with a cold aqueous solution of saturated NaHCO3 (80 mL)
11. 11
    기타After drying
12. 12
    기타removal of the solvent
13. 13
    기타the residue was purified with a silica gel chromatography (heptane/ethyl acetate, gradient eluting)

실험 절차

To a 100 mL dry round bottom flask were added tetrahydro-pyran-4-carboxylic acid (2.8 g, 21.5 mmol), thionyl chloride (2.8 mL, 34.4 mmol). The mixture was refluxed for 45 minutes, then all the volatile materials were rotary-evaporated. To the residue, anhydrous CH2Cl2 (10 mL) was added. The resulting solution was cooled to 0° C., and pyridine (2.63 g, 21.5 mmol) was added, followed by a solution of 4-hydroxybenzaldehyde (2.04 g, 25.8 mmol) in anhydrous CH2Cl2 (30 mL). The reaction mixture was stirred and warmed from 0° C. to room temperature slowly, then at room temperature overnight. To the reaction mixture, water (60 mL) was added and the CH2Cl2 layer was separated. The aqueous layer was extracted continually with CH2Cl2 (50 mL×3). The combined CH2Cl2 solution was washed with a cold aqueous solution of saturated NaHCO3 (80 mL). After drying and removal of the solvent, the residue was purified with a silica gel chromatography (heptane/ethyl acetate, gradient eluting) to give 4-formylphenyl tetrahydro-2H-pyran-4-carboxylate (4.40 g) as colorless oil. Yield: 87%. 1H NMR (CDCl3, 300 MHz): δ=9.97 (s, 1H), 7.91 (d, J=8.7 Hz, 2H), 7.27 (d, J=8.4 Hz, 2H), 4.06-4.00 (m, 2H), 3.55-3.47 (m, 2H), 2.88-2.81 (m, 1H), 2.03-1.88 (m, 4H). 13C NMR (CDCl3, 75.5 MHz): δ=190.9, 172.2, 155.3, 133.9, 131.1, 122.2, 115.9, 66.8, 40.1, 28.4.

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