Author(s)

Shigeki Furukawa, Kensuke Otokawa, Osamu Sasaki, Ken Nakayasu, Tatsuaki Yamaguchi

College of Industrial Technology, Nihon University, Chiba, Japan.
Faculty of Engineering, Chiba Institute of Technology, Chiba, Japan.
Faculty of Engineering, Chiba Institute of Technology, Chiba, Japan Instrumental Analysis Division, Center for Supports to Research and Education Activities, Kobe University, Kobe, Japan.

A direct regioselective preparation of 2-hydroxynaphthalene-6-carboxylic acid, a useful industrial intermediate of aro-matic polyester from 2-naphthol was conducted by use of excess amount of K2CO3 (10-fold molar to 2-naphthol) under supercritical CO2 at 10 MPa and 473 K. The obtained yield under this condition was ca. 20 mol% to 2-naphthol. The further investigations may provide an alternative process to the conventional Kolbe-Schmitt reaction, because of no use of strong alkali and recoverability of K2CO3. Theoretical explanation about the regioselectivity was achieved by means of DFT calculations.

Supercritical CO₂; CO₂ Utilization; Kolbe-Schmitt Reaction; Carboxylation; 2-Naphthol; Potassium Carbonate; 2-Hydroxynaphthalene-6-carboxylic Acid; DFT Calculation

S. Furukawa, K. Otokawa, O. Sasaki, K. Nakayasu and T. Yamaguchi, "Regioselective Direct Carboxylation of 2-Naphthol with Supercritical CO₂ in the Presence of K₂CO₃," International Journal of Organic Chemistry, Vol. 3 No. 3, 2013, pp. 210-213. doi: 10.4236/ijoc.2013.33028.