Hydrochloric Acid → 2-Chloro-6-ethoxybenzo[d]thiazole

Participants

Reaction Conditions

Reaction Steps

20 g (0.103 mol) of 2-amino-6-ethoxy-benzothiazole are dissolved in 100 ml of glacial acetic acid and 52 ml of concentrated hydrochloric acid and whilst cooling with ice the mixture is diazotised with 7.4 g (0.108 mol) of sodium nitrite in 15 ml of water. Then the solution of the diazonium salt is added batchwise to a suspension of 13.6 g (0.137 mol) of copper-I-chloride in 65 ml of concentrated hydrochloric acid and stirred for 20 minutes at 30° C. Then the mixture is diluted with 800 ml of ice water and the crystals formed are suction filtered. To purify them they are chromatographed on silica gel (eluant: petroleum ether/ethyl acetate=6:1). Yield: 61.7% of theory, Melting point: 60-61° C.

Provenance & Evidence