Bromine → 7-Chloro-4-methoxy-1,3-benzothiazol-2-amine

Participants

Reaction Conditions

Reaction Steps

A solution of 1-(2-methoxy-5-chlorophenyl)-2-thiourea (1 mmole) in chloroform (10 mL) was cooled to 10° C. and treated with bromine (2.2 mmole) in chloroform (10 mL). The reaction was stirred at 10° C. for 20 min and at room temperature for 0.5 h. The resulting suspension was heated at reflux for 0.5 h. The precipitate was collected via filtration (washed with CH2Cl2) to give 2-amino-4-methoxy-7-chlorobenzothiazole which was subjected to Steps A, B, C and D of Example 27 to give 2-amino-4-phosphonomethoxy-6-bromo-7-chloro benzothiazole (28.1). mp>220° C.(dec.). Anal. calcd. for C8H7N2O4PSClBr: C: 25.72; H: 1.89; N: 7.50. Found: C: 25.66; H: 1.67; N: 7.23.

Provenance & Evidence