Diisopropylethylamine → Tert-butyl [4-(5-benzyl[1.3.4]thiadiazol-2-ylcarbamoyl)phenyl]carbamate

Participants

Reaction Conditions

Reaction Steps

1 g of 4-tert-butoxycarbonylaminobenzoic acid (4.21 mmol, 1 eq.) is placed in 12 mL of a 5/1 mixture of dichloromethane and dimethylformamide with stirring. 0.81 g of 5-benzyl-1,3,4-thiadiazol-2-amine (4.21 mmol, 1 eq.), 0.97 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (5.05 mmol, 1.2 eq.), 0.97 g of hydroxybenzotriazole (6.32 mmol, 1.5 eq.) and 1.74 mL of diisopropylethylamine (10.52 mmol, 2.5 eq.) are successively added. After 42 hours at room temperature, the medium is heated at 60° C. for 6 hours. 0.40 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (2.1 mmol, 0.5 eq.) and 0.322 g of hydroxybenzotriazole (3.16 mmol, 0.5 eq.) are added. After 18 hours, the medium is diluted with dichloromethane and water. The organic phase is separated out by settling, washed with water, dried over magnesium sulfate, filtered and evaporated. The residue is chromatographed on silica gel with a gradient of ethyl acetate in heptane ranging from 0% to 50%. The organic phase is evaporated to give 0.2 g of tert-butyl [4-(5-benzyl[1.3.4]thiadiazol-2-ylcarbamoyl)phenyl]carbamate.

Provenance & Evidence