Reaktion #475602

Reaktionsgleichung

material 9

5-Bromo-3-(4-chloro-phenyl)-isothiazole-4-carboxylic acid tert-butyl ester

water

Na2CO3

→

Isothiazole

3-(4-Chloro-phenyl)-5-phenyl-isothiazole-4-carboxylic acid tert-butylester

Lösungsmittel

DME

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe mixture is degassed with argon for 5 min
2. 2
   workup.ADDITIONPd(dppf)Cl2 (121 mg) is added
3. 3
   Sonstigethe tube is sealed
4. 4
   workup.ADDITIONThe reaction mixture is diluted with EtOAc
5. 5
   Waschenwashed with water and brine
6. 6
   SonstigeThe organic layer is dried
7. 7
   Einengenconcentrated
8. 8
   SonstigeThe residue is purified by flash column chromatography

Vorschrift

Starting material 9 (1.12 g) is dissolved in DME (12 ml) and to this are added 439 mg of 10, water (5 ml) and 954 mg of Na2CO3. The mixture is degassed with argon for 5 min. Pd(dppf)Cl2 (121 mg) is added, the tube is sealed and the reaction mixture is heated at 100° C. in the microwave for 15 min. TLC (Hep/EtOAc, 80/20) shows a good conversion into a slower moving spot. The reaction mixture is diluted with EtOAc and washed with water and brine. The organic layer is dried and concentrated. The residue is purified by flash column chromatography using 5% diisopropyl ether in heptane as eluent. Isothiazole 11 is obtained in good yield as a white crystalline solid.

Quelle