Reaktion #1952985

Reaktionsgleichung

HBr

6

methyl 5-[bis(2-bromoethyl)amino]-4-(methylsulfonyl)-2-nitrobenzoate

KOH

→

5-[bis(2-bromoethyl)amino]-4-(methylsulfonyl)-2-nitrobenzoic acid

Ausbeute 72.0%

Lösungsmittel

dioxane MeOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   Einengenconcentrated to a small volume under reduced pressure
2. 2
   workup.ADDITIONdiluted with saturated aqueous NaBr (20 mL)
3. 3
   SonstigeThe resulting semi-solid was isolated
4. 4
   Sonstigecrystallized twice from MeOH/H2O

Vorschrift

A solution of 6 (1.00 g, 2.05 mmol) in a dioxane/MeOH (1:1, 20 mL) was treated at 10° C. with 4N aqueous KOH (5 mL), and stirred at 10° C. for 45 min. The mixture was acidified to pH 2 with1 N aqueous HBr, concentrated to a small volume under reduced pressure, and then diluted with saturated aqueous NaBr (20 mL). The resulting semi-solid was isolated and crystallized twice from MeOH/H2O to give 5-[bis(2-bromoethyl)amino]-4-(methylsulfonyl)-2-nitrobenzoic acid (7) (0.70 g, 72%): mp 174-176° C.; 1H NMR [(CD3)2SO] δ 8.50 (s, 1 H), 7.88 (s, 1 H), 3.79 (t, J=7.0 Hz, 4 H), 3.62 (t, J=7.0 Hz, 4 H), 3.48 (s, 3 H). Anal. (C12H14Br2N2O6S) C, H, N.

Quelle