Tetrahydrofuran → 1-Hydroxy-2-naphthoic acid

Participants

Reaction Steps

To a stirred solution of 385 (8.11 mmol) in a mixture of THF and MeOH (1:1, v/v, 100 mL) was added Raney nickel (˜2 mL, 50% suspension in water). Hydrazine (N2H4, 32.0 mmol, 4 equiv) was added in portions over a period of 30 minutes. Once effervescence had ceased, TLC analysis (15:2:0.1, CH2Cl2/MeOH/NH4OH) indicated complete conversion of the starting material to a compound that had lower Rf than the starting material (stained spontaneously with PMA/Ce stain without requiring heating). The suspension was diluted with THF (100 mL) and filtered through a pad of Celite on a fritted funnel. The supernatant was concentrated to yield 1-hydroxy-[2]naphthoic acid-(4-amino-anilide) (111) (7.8 mmol, 96% yield) as a dark purple solid. 1H NMR (400 MHz, DMSO-d6) δ=5.06 ppm (br s, 2H), 6.57 (br d, 2H, J=9 Hz), 7.29 (br d, 2H, J=9 Hz), 7.39 (d, 1H, J=9 Hz), 7.53 (app. td, 1H, J=1, 8 Hz), 7.62 (app. td, 1H, J=1, 7 Hz), 7.86 (d, 1H, J=8 Hz), 8.05 (d, 1H, J=9 Hz), 8.26 (d, 1H, J=8 Hz), 10.13 (br s, 1H). LC-MS: m/e 279.2 [M+1]+.

Provenance & Evidence