反应详情

204 parts of technical sodium β-naphtholate melt containing 100 parts of sodium-β -naphtholate and 100 parts of sodium sulfite is stirred at 250° to 260° C. with 150 parts of methylphenylindan for fifteen minutes. The undissolved sodium sulfite is allowed to settle and the hot solution of sodium β-naphtholate in methylphenylindan at 260° C. is pumped into a stirred autoclave which has been preheated to 255° C. The autoclave is closed and at an internal temperature of 255° C. dry carbon dioxide is pressed in up to a pressure of 5 atmospheres. Carboxylation and processing are carried out analogously to Example 1. 34 parts of 2-hydroxynaphthalene-3-carboxylic acid having a melting point of 212° to 215° C. is obtained (60% of theory based on β-naphthol used up).

1. customat 260° C.
2. customhas been preheated to 255° C