3-Chloro-1,2-benzisothiazole

White Solid

1 L four-neck flask equipped with a stirrer, a thermometer and a condenser tube was charged with 75.6 g (0.5 mol) of 1, 2-benzisothiazol-3-one, 54.8 g (0.75 mol) of N, N-dimethylformamide and 100.0 g of chlorobenzene. While stirring, 71.4 g (0.6 mol) of thionyl chloride was added dropwise thereto over 1 hour at 70° to 80° C., and the mixture was reacted at the same temperature for 8 hours. After terminating the reaction, the liquid reaction mixture was concentrated, and a crude product obtained was distillated under reduced pressure of 0.93 kPa at 128° C. to give 75.1 g (0.45 mol) of 3-chloro-1, 2-benzisothiazole. The yield based on the 1, 2-benzisothiazol-3-one was 90percent.General procedure: The substrate was dissolved or suspended in toluene (or acetonitrile where specified below) and DMF (2.5 equiv) or formamide (1.2 equiv) was added. Under an atmosphere of nitrogen, POClExample 6 Example 5 was repeated, except that 4 kg of 93percent by weight pure benzisothiazolone and 90 g of 1, 3-dimethylimidazolidinone in 5 l of chlorobenzene were phosgenated. To obtain the reaction product, 200 ml of high boiling paraffin oil were added prior to the vacuum distillation, and a Vigreux column of 20 cm in length was used. 3-Chlorobenzisothiazole of a purity of 99.4percent by weight was obtained in a yield of 92.7percent of theory.1 L four-neck flask equipped with a stirrer, a thermometer and a condenser tube was charged with 75.6 g (0.5 mol) of 1, 2-benzisothiazol-3-one, 54.8 g (0.75 mol) of N, N-dimethylformamide and 100.0 g of chlorobenzene. While stirring, 71.4 g (0.6 mol) of thionyl chloride was added dropwise thereto over 1 hour at 70° to 80° C., and the mixture was reacted at the same temperature for 8 hours. After terminating the reaction, the liquid reaction mixture was concentrated, and a crude product obtained was distillated under reduced pressure of 0.93 kPa at 128° C. to give 75.1 g (0.45 mol) of 3-chloro-1, 2-benzisothiazole. The yield based on the 1, 2-benzisothiazol-3-one was 90percent.Similarly to Example 1, 406 g of dry, 93percent pure benzisothiazolone with 20.3 g of tetramethylurea were phosgenated in o-chlorobenzene. Vacuum distillation gave 3-chlorobenzisothiazole in a yield of 84.9percent of theory.General procedure: The substrate was dissolved or suspended in toluene (or acetonitrile where specified below) and DMF (2.5 equiv) or formamide (1.2 equiv) was added. Under an atmosphere of nitrogen, POCl3 (1.2 equiv) was added dropwise to control any exotherm. The mixture was either stirred at 20 °C or warmed in an Emrys Optimizer microwave reactor (see below) until complete reaction was observed by HPLC. The mixture was cooled when necessary and poured into saturated K2CO3 solution. The solid product was then isolated by vacuum filtration and drying in vacuo at 40 °C.In a three-necked bottle equipped with a thermometer, a dropping funnel and a condenserAdd the intermediate 1 obtained in the previous step, mix and stir with 5 ml of N, N-dimethylformamide and 10 ml of chlorobenzene in an oil bath at 75 ° C.3.2 ml of thionyl chloride was slowly dropped into the reaction system, and reacted at this temperature for 10 hours.After cooling, the solvent was evaporated to dryness The product was isolated by column chromatography. The combined yield in two steps was 77.2percent

Molecular Weight:169.63
XLogP3:3.3
Hydrogen Bond Acceptor Count:2
Exact Mass:168.9752980
Monoisotopic Mass:168.9752980
Topological Polar Surface Area:41.1
Heavy Atom Count:10
Complexity:131
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes