Dicyclohexylcarbodiimide → cis-2-{(3,3-Dimethylbutyl)-[2-(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1lambda6-benzo[1,2,4]thiadiazin-3-yl)acetyl]amino}-cyclopentanecarboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of cis-2-(3,3-dimethylbutylamino)-cyclopentanecarboxylic acid ethyl ester (54.5 mg, 0.226 mmol) in N,N-dimethylformamide (5.0 mL) was added (7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-acetic acid (prepared as described in Example 1j, 150.6 mg, 0.452 mmol) and a 1.0 M solution of N,N′-dicyclohexylcarbodiimide in dichloromethane (0.23 mL, 0.23 mmol). After stirring at 25° C. for 12 h, the mixture was diluted with dichloromethane and the precipitated N,N′-dicyclohexylurea byproduct was removed by filtration. The filtrate was concentrated and dried in vacuo to afford the crude product, cis-2-{(3,3-dimethylbutyl)-[2-(7-methanesulfonylamino-1,1-dioxo-1,4-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)acetyl]amino}-cyclopentanecarboxylic acid ethyl ester as a yellowish oil. The crude product was used in the next step without further purification. LC-MS (ESI) calcd for C24H36N4O7S2 556.20, found 557.3 [M+H+].

Provenance & Evidence