Reaktion #9261

Reaktionsgleichung

sodium carbonate

N-(6-bromo-1,3-benzothiazol-2-yl)-N′-ethylurea

ethylene glycol dimethyl ether

5-chlorothiophene-2-boronic acid

→

N-[6-(5-chloro-2-thienyl)-1,3-benzothiazol-2-yl]-N′-ethylurea

Ausbeute 16.0%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe suspension was evacuated
2. 2
   SonstigeThe pressure tube was then sealed tightly
3. 3
   Temperaturheated to about 85–90° C. for about 12–20 hours
4. 4
   Sonstigethen purified by preparative HPLC

Vorschrift

A 40 ml pressure tube was charged with about 100 mg N-(6-bromo-1,3-benzothiazol-2-yl)-N′-ethylurea, and about 2 ml ethylene glycol dimethyl ether. The slurry was stirred via magnetic stirbar followed by evacuation then release to nitrogen atmosphere (3 times). Next about 6 mol percent Pd(PPh3)4 was added, followed by about 1.1 eq of 5-chlorothiophene-2-boronic acid. Following addition of about 3 equivalents sodium carbonate in about 0.5 ml water, the suspension was evacuated and released to nitrogen atmosphere 3 times. The pressure tube was then sealed tightly and heated to about 85–90° C. for about 12–20 hours. The reaction was cooled to room temperature then purified by preparative HPLC to yield 16% of N-[6-(5-chloro-2-thienyl)-1,3-benzothiazol-2-yl]-N′-ethylurea. 1H NMR 1.1 (t, 3H), 3.2 (m, 2H), 6.75 (m, 1H), 7.18 (d, 1H), 7.38 (m, 1H), 7.6 (m, 2H), 8.19 (d, 1H), 10.75 (br s, 1H); LC/MS 3.86 min, 338 (M+1), 336 (M−1).

Quelle