4-Chlorophenyl Isocyanate → HCID 21242496, compound

Participants

Reaction Steps

2-(4-Chlorophenylaminocarbonylamino)-5-iodobenzoic acid was prepared by adding a solution of 4-chlorophenyl isocyanate (15.4 g) in ethyl acetate (60 ml) dropwise, at room temperature, to a stirred suspension of 5-iodoanthranilic acid (26.3 g) in ethyl acetate (150 ml). The mixture was heated at reflux for 1 hour, cooled to ambient temperature and the solid removed by filtration, to give 34 g of the substituted benzoic acid. This (34 g) was added to absolute alcohol (250 ml) saturated with hydrogen chloride gas and heated at reflux for 40 minutes. When cool, the solid was filtered and washed with absolute alcohol (50 ml) to give 27.1 g of 3-(4-chlorophenyl)-6-iodoquinazoline-2,4(1H,3H)-dione, mp 324°-6° C. This product (26.9 g) was added slowly to a mixture of pyridine (25 ml) and phosphoryl chloride (250 ml). The mixture was heated at reflux for 6 hours, when a solution developed. When cool, excess phosphoryl chloride and pyridine were removed by distillation in vacuo. The residue was cautiously added to ice water (500 ml) and the solid filtered. This solid was extracted with dichloromethane (100 ml), the extract concentrated in vacuo and chromatographed on silica using dichloromethane to give 9.7 g of 2-chloro-3-(4-chlorophenyl)-6-iodoquinazolin-4(3H)-one, mp 178°-180° C. This was then treated with 1,2,4-triazole and potassium carbonate in a similar manner to Example 1 to give 3-(4-chlorophenyl)-2-(1,2,4-triazol-1-yl)-6-iodoquinazolin-4(3H)-one, mp 206°-208° C. (Compound 2).

Provenance & Evidence