2-Mercaptobenzoic Acid → 2-{[2-(carboxymethyl)-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl]sulfanyl}benzoic acid

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Reaction Steps

A mixture of 6-chloro-1,3-dioxo-1H-benz[de]isoquinoline-2(3H)-acetic acid (10.0 g, 34.5 mmoles, described in Example 2); 2-mercaptobenzoic acid (5.85 g, 37.9 mmoles) and anhydrous potassium carbonate (9.54 g, 37.9 mmoles) in dimethylformamide (300 ml) was heated at reflux for 3 hr. The product in the form of its sodium salt was precipitated from the reaction mixture. The precipitate was collected by filtration and dissolved in water. The solution of the sodium salt was rendered acidic with 2 N hydrochloric acid. The resulting precipitate was collected, dried and crystallized from dimethylformamide and water to give 9.0 g of the title compound; mp 339°-341° C.; UV (MeOH) 231, 254, 336 and 346, ε=31,450, 15,810, 8,760 and 9,210, respectively; IR (CHCl3) 2900, 1725, 1710, 1675 cm-1 ; NMR (CDCl3) δ 4.7 (s, 2H), 6.5-8.6 (m, 9H), 13.0 (broad, 1H); Anal. Calc'd: C, 61.91%; H, 3.22%; N, 3.44%; Found: C, 61.51%; H, 3.21%; N, 3.73%.

Provenance & Evidence