ChemicalBook CAS DataBase List 3-CARBETHOXYUMBELIFERONE

3-CARBETHOXYUMBELIFERONE synthesis

11synthesis methods

Product Name:3-CARBETHOXYUMBELIFERONE
CAS Number:6093-71-6
Molecular formula:C12H10O5
Molecular Weight:234.2

105-53-3

95-01-2

6093-71-6

The general procedure for the synthesis of ethyl 7-hydroxy-2-oxo-2H-benzopyran-3-carboxylate from 2,4-dihydroxybenzaldehyde (3.70 mmol) and diethyl malonate (7.90 mmol) was as follows: piperidine (10 drops) was added to a solution of diethyl malonate of 2,4-dihydroxybenzaldehyde and the resulting mixture was stirred and reacted for 2 hours at room temperature. Upon completion of the reaction, the reaction mixture was acidified with 10% aqueous hydrochloric acid solution (5 mL). The precipitated solid was collected by filtration and washed with cold water (10 mL). The crude product was purified by fast column chromatography using dichloromethane:ethyl acetate (70:30, v/v) as eluent to afford the target compound ethyl 7-hydroxy-2-oxo-2H-chromene-3-carboxylate (0.735 g, 97% yield). The structure of the product was confirmed by 1H NMR (400 MHz, DMSO-d6) and 13C NMR (100 MHz, DMSO-d6): 1H NMR δ 1.28 (t, J = 7.1 Hz, 3H), 4.24 (q, J = 7.1 Hz, 2H), 6.71 (d, J = 1.8 Hz, 1H), 6.83 (dd, J = 1.8, 8.3 Hz, 1H), 7.74 (d, J = 8.3 Hz, 1H), 8.66 (s, 1H), 11.07 (s, 1H); 13C NMR δ 14.1, 60.8, 101.7, 110.4, 113.9, 120.0, 132.1, 149.4, 156.3, 157.0, 162.9, 164.0.

105-53-3
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$5.00/25g

95-01-2
494 suppliers
$10.00/1g

6093-71-6
122 suppliers
$25.00/5mg

Yield: 97%

Reaction Conditions:

with piperidine at 20; for 2 h;Knoevenagel condensation;

Steps:

Ethyl 7-hydroxy-2-oxo-2H-chromene-3-carboxylate (3)⁶
To a solution of 2,4-dihydroxybenzaldehyde (3.70 mmol) in diethyl malonate (7.90 mmol) piperidine (10 drops) was added, and the resulting solution was stirred for 2 hours at r.t. The resulting solution was then acidified with an aqueous solution of HCl10% (5 mL). The precipitate was filtrated and washed with cold water (10 mL). The desired product was purified by flash chromatography using dichloromethane : ethyl acetate (70: 30) as eluent furnishing 3 (0.735g) in 97% yield. ¹H NMR (400 MHz, DMSO-d6) : 1.28 (t, J=7.1 Hz, 3H), 4.24 (q, J=7.1 Hz, 2H), 6.71 (d, J= 1.8Hz, 1H), 6.83 (dd, J= 1.8, 8.3Hz, 1H), 7.74 (d, J= 8.3Hz, 1H), 8.66 (s, 1H), 11.07 (s, OH). ¹³C NMR (100 MHz, DMSO-d6): 14.1, 60.8, 101.7, 110.4, 112.0, 113.9, 132.1, 149.4, 156.3, 157.0, 162.9, 164.0.

References:

Vieira, Lucas C.C.;Paix?o, Márcio Weber;Corrêa, Arlene G. [Tetrahedron Letters,2012,vol. 53,# 22,p. 2715 - 2718] Location in patent:experimental part