反应详情

温度

60 °C

A suspension of 2,6-Naphthalendicarboxylic acid (10.8 g, 50 mmol) in anhydrous DMF (400 ml) with 1,8-diazabicyclo[5,4,0]undec-7-ene (DBU, 7.5 ml, 50 mmol) was heated to near boiling, then kept stirring at 60° C. To it was added benzyl bromide solution (6 ml, 50 mmol, in 200 ml of DMF) dropwise. After 3 hours the solution was concentrated and 0.5 N HCl/brine (400 ml) was added, extracted with EtOAc and the combined organic extracts were washed with H2O, and taken to dryness to yield a white solid. The solid was dissolved in EtOAc, and NEt3 was added with slight warming to effect total dissolution of all solid. This solution was filtered through silica gel. Initial elution with EtOAc provided 2,6-naphathalenedicarboxylic acid dibenzyl ester. Subsequent elution with EtOAc/Acetic acid (99/1) brought desired product. Evaporation of solvent and suspension of the resulting solid in petroleum ether, following by collection and drying of solid gave pure product 2,6-Naphthalenedicarboxylic acid monobenzyl ester (5 g, 33%). 1H NMR (360 MHz, DMSO-d6) δ13 (br. 1H, —COOH), 8.725 (s, 1H, Ar—H), 8.664 (s, 1H, Ar—H), 8.251(d, J=8.2 Hz, 2H, Ar—H), 8.087-8.044 (m, 2H, Ar—H), 7.539 (d, J=7.0 Hz, 2H, Ar—H), 7.450-7.350 (m, 3H, Ar—H), 5.439 (s, 2H, —COOCCH2—), MS m/e 305 [M+−1].

1. temperaturewas heated
2. concentrationAfter 3 hours the solution was concentrated
3. addition0.5 N HCl/brine (400 ml) was added
4. extractionextracted with EtOAc
5. washthe combined organic extracts were washed with H2O
6. customto yield a white solid
7. temperaturewith slight warming
8. dissolutiondissolution of all solid
9. filtrationThis solution was filtered through silica gel
10. washInitial elution with EtOAc