Hydrochloric Acid → 2-{(2-Cyclopropyl-ethyl)-[2-(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1lambda6-benzo[1,2,4]thiadiazin-3-yl)-acetyl]-amino}-cycloheptanecarboxylic acid methyl ester

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Reaction Conditions

Reaction Steps

The crude cis-2-(2-cyclopropyl-ethylamino)-cycloheptanecarboxylic acid methyl ester (260.5 mg, 1.09 mmol) was mixed with (7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetic acid (prepared as described in Example 1j, 399 mg, 1.2 mmol) and dissolved in N,N-dimethylformamide (9 mL). N-Methylmorpholine (264 μL, 2.4 mmol) was added followed by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (230 mg, 1.2 mmol). The resulting mixture was shaken at 25° C. overnight. A 1.0 M aqueous hydrochloric acid solution (11 mL) was added (pH=2) and the mixture was extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with brine (40 mL), dried over sodium sulfate, filtered, and concentrated in vacuo. The residue was further dried in vacuo for 5.5 h to afford the crude product, 2-{(2-cyclopropyl-ethyl)-[2-(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetyl]-amino}-cycloheptanecarboxylic acid methyl ester, containing 2-[2-(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetylamino]-cycloheptanecarboxylic acid methyl ester as a side product, as a brown oil. This crude product was directly used in the next step without further purification. LC-MS (ESI) calcd for C24H34N4O7S2 554.19, found 555.3 [M+H+] and LC-MS (ESI) calcd for C19H26N4O7S2 486.12, found 487.3 [M+H+]+.

Provenance & Evidence