1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → tert-Butyl 6-[[[6-(8-methyl-4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridyl]carbonyl]amino]hexylcarbamate

Participants

Reaction Conditions

Reaction Steps

6-(8-Methyl-4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridinecarboxylic acid (1.5 g, 5.0 mmol) was dissolved in DMF (15 ml) and N-(tert-butoxycarbonyl)-1,6-diaminohexane (2.1 g, 10.0 mmol), WSC (3.0 g, 15.5 mmol) and HOBt (2.0 g, 14.9 mmol) were added thereto. The reaction mixture was stirred at 80° C. for 10 hrs and combined with ethyl acetate and water. The organic layer was washed with saturated brine and dried over magnesium sulfate. The solvent was evaporated and the residue was subjected to a silica gel column chromatography. The fractions eluted with ethyl acetate-hexane (4:1, v/v) were collected, concentrated and recrystallized from hexane-tetrahydrofuran to give the titled compound (1.1 g, 45%) as white crystals.

Provenance & Evidence