Chloroacetic Acid → 2-(Chloromethyl)benzothiazole

Using literature procedures (Addison, A. W.; Nageswara Rao, T.; Wahlgren, C. G. J. Heterocyclic Chem. 1983, 20, 1481–1484) a substituted 2-aminophenol (or a 2-aminothiophenol (5 mmol)) was mixed with chloroacetic acid (940 mg, 10 mmol) in polyphosphoric acid (5 mL), and the viscous mixture was then heated to 120° C. for 3 hours. The reaction was then cooled, and diluted with water (˜20 mL) and then neutralized with potassium carbonate to pH˜7. The mixture was then extracted with ethyl acetate, and the combined organic fractions were then dried over MgSO4 and concentrated. The residue was then purified by column chromatography on silica gel (50% ethyl acetate in hexanes) to afford the desired 2-chloromethylbenzoxazole (or 2-chloromethylbenzothiazole).

1. temperatureThe reaction was then cooled
2. extractionThe mixture was then extracted with ethyl acetate
3. dry with materialthe combined organic fractions were then dried over MgSO4
4. concentrationconcentrated
5. customThe residue was then purified by column chromatography on silica gel (50% ethyl acetate in hexanes)

ORD record

ord-1b495aa703b04744bb5cf439eed00b5d

Source dataset

uspto-grants-2006_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07084155B2