Hydrochloric Acid → HCID 18614937, compound

Participants

Reaction Conditions

Reaction Steps

To a mixture of 4-(6,6,9,9-tetramethyl-6,7,8,9-tetrahydro-2H-benzo[g]chromen-4-ylidenemethyl)-benzoic acid methyl ester (220 mg, 0.56 mmol) in methanol (10 mL) was added concentrated HCl (0.05 mL) and the solution was allowed to stir at 85° C. for 12 h. The solution was quenched with aqueous saturated NaHCO3 solution (100 mL), extracted with EtOAc, dried (Na2SO4), and concentrated. The acid was obtained by hydrolysis according to the standard conditions and was purified by silica gel preparative TLC (50% EtOAc/Hexane) to afford 4-(6,7,8,9-tetrahydro-6,6,9,9-tetramethyl2H-benzo[g]chromen-4-ylmethyl)-benzoic acid (133) (89%) as a white solid: m.p. 200-201° C.; IR (neat) 2969 s, 2958 s, 2922 s, 2361 m, 1689 s, 1608 m, 1419 s, 1408 s, 1286 m, 1174 s, 1018 s cm−1; 1H NMR (400 MHz, CDCl3) δ 8.04 (½ ABq, 2H, J=8.0 Hz, ArH), 7.37 (½ ABq, 2H, J=8.0 Hz, ArH), 6.98 (s, 1H, ArH), 6,74 (s, 1H, ArH), 5.43 (broad t, 1H, olefinic), 4.75 (m, 2H, ring CH2), 3.79 (s, 2H, benzylic CH2), 1.59 (s, 4H, 2CH2), 1.22 (s, 6H, 2CH3), 1.13 (s, 6H, 2CH3).

Provenance & Evidence