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ChemicalBook CAS DataBase List 6-CARBOXYL-4-PHENYL-3,4-DIHYDROCOUMARIN
356782-33-7

6-CARBOXYL-4-PHENYL-3,4-DIHYDROCOUMARIN synthesis

2synthesis methods
-

Yield:356782-33-7 78%

Reaction Conditions:

with sulfuric acid;acetic acid in water at 100; for 18 h;

Steps:

1 1.

1. (R,S)-4-Phenyl-2-chromanone-6-carboxylic acid (Formula 2a) A mixture of cinnamic acid (100 g, 0.68 mol), methyl 4-hydroxybenzoate (108 g, 0.71 mol) and acetic acid (80 ml) is heated to 100° C. 80 ml of 96% sulfuric acid are then added to the resulting clear solution, while stirring. After 2 hours, crystal formation begins. Stirring is continued at the same temperature for 16 hours, the mixture is cooled to ambient temperature and diluted with 500 ml water. The precipitated crystal mass is filtered off, washed with diethyl ether and dried in vacuo. Crude yield: 142 g (78% of theory), pale beige crystals. Mp 246° C. 1H-NMR (DMSO-d6): 3.18 (d, 2H, J=6.6 Hz, CH2), 4.62 (t, 1H, J=6.6 Hz, CH), 7.14-7.43 (m, 6H), 7.62 (s, 1 H), 7.90 (d, 1 H, J=8.6 Hz). 13C-NMR (DMSO-d6): 35.93, 39.26,117.20,126.81, 127.13,127.65,127.70,129.24, 129.95, 130.25, 140.91, 154.80, 166.66,167.30

References:

US2003/212292,2003,A1 Location in patent:Page/Page column 5