Reaktion #832965

Reaktionsgleichung

NaHSO3

chlorine

(4,6-dimethoxy-1-naphthalenyl)ethanone

chlorine

HCl

NaOH

chlorine

→

4,6-dimethoxy-1-naphthalenecarboxylic acid

Ausbeute 75.4%

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas absorbed into the solution
2. 2
   Temperaturcooled in an ice bath
3. 3
   SonstigeThe resulting precipitate was collected
4. 4
   Waschenwashed well with water
5. 5
   Trocknendried over P2O5
6. 6
   Sonstigerecrystallized from methanol

Vorschrift

A stream of chlorine gas was passed through a cooled solution of NaOH (17.28 g, 0.432 mole) in water (24 ml) containing 100 g of ice until 12.7 g (0.18 mole) of chlorine was absorbed into the solution. Solid (4,6-dimethoxy-1-naphthalenyl)ethanone [9.2 g, 0.04 mole, described by N. P. Buu-Hoi, J. Org. Chem., 21, 1257 (1956)], was added at 20°-22° C. to the chlorine solution. The mixture was stirred at 65° C. for one hr, cooled in an ice bath and treated with NaHSO3 (5 g) in water (20 ml). The mixture was made neutral by the addition of dilute HCl. The resulting precipitate was collected, washed well with water, dried over P2O5 and recrystallized from methanol to give 4,6-dimethoxy-1-naphthalenecarboxylic acid (7.0 g); mp 227°-229° C.; NMR (DMSO-d6) δ 3.85 (s, 3H), 4.0 (s, 3H), 7.7 (m, 5H); IR (white mineral oil) 2900, 1670 cm-1 ; UVλmax (MeOH) 339 nm (ε4,910), 328 (4500), 304 (8,180), 240 (40,100); Anal Calcd: C, 67.23% H, 5.21%; Found: C, 67.15% H, 5.23%.

Quelle