Cyclopropanecarboxylic acid → HCID 86612146, compound

Participants

Reaction Steps

A solution of 2-aminobenzothiazol-6-ol (intermediate 1) (850 mg, 4.6 mmol), cyclopropanecarboxylic acid (1.564 g, 18.1 mmol), N,N-diisopropylethylamine (3.6 ml, 24.4 mmol) and HBTU (4.1 g, 5.53 mmol) in 40 ml of dimethyl-formamide, in a 100 ml round-bottomed flask equipped with a magnetic bar, is stirred at room temperature for 16 hours. 150 ml of water are added to the reaction medium, the mixture is extracted with ethyl acetate and the extracts are washed with saturated sodium chloride solution, dried over magnesium sulfate and concentrated to dryness. The residue obtained is washed with ethyl acetate to give 893 mg of cyclopropanecarboxylic acid 2-(cyclo-propanecarbonylamino)benzothiazol-6-yl ester. LC/MS: [M+H]+=303.18, retention time=3.53 min. A solution of lithium hydroxide monohydrate (200 mg, 4.768 mmol) in 50 ml of methanol and 5 ml of water is added to this product. The reaction medium is refluxed with stirring for 1 hour. The reaction medium is concentrated, acidified to pH 1 with 2N hydrochloric acid solution, diluted with 100 ml of water and extracted with ethyl acetate. The organic phase is washed with water and then with saturated sodium chloride solution and evaporated to dryness to give 500 mg of cyclopropanecarboxylic acid (6-hydroxybenzothiazol-2-yl)amide in a yield of 72% (beige-colored powder).

Provenance & Evidence