6-(2-Chloroacetyl)benzo[d]thiazol-2(3H)-one synthesis

Yield:99615-55-1 98%

Reaction Conditions:

with carbon disulfide;aluminum (III) chloride for 1.66 h;Cooling with ice;Reflux;

Steps:

20.1 Step 1


Step 1
Benzothiazole-2(3H)-one 20-a (500 mg, 3.307 mmol) was suspended in carbon disulfide (8 ml), anhydrous aluminum chloride (2.65 g, 19.841 mmol) was added portionwise under ice bath, then chloroacetyl chloride (324 ul, 4.299 mmol) was slowly added dropwise.
The reaction mixture was stirred at room temperature for 10 minutes and at reflux for 1.5 hours.
The reaction was quenched with ice water and concentrated.
Ice water (15 ml) and 4N hydrochloric acid (10 ml) was added thereto.
The mixture was stirred for 2 hours at room temperature, filtered, the filter cake was washed with ice water twice, dried to give 20-b as a pink solid (740 mg, yield: 98%). ESI-MS (m/z): 227.9 [M+H]⁺. ¹H-NMR (300 Hz, DMSO-d₆): δ ppm 12.35 (s, 1H), 8.25 (d, 1H), 7.89 (dd, 1H), 7.20 (d, 1H), 5.13 (s, 2H).

References:

US2017/158680,2017,A1 Location in patent:Paragraph 0392; 0393; 0394