Diisopropylethylamine → HCID 118248863, compound

Participants

Reaction Steps

To a mixture of a mixture (1.85 g) of 8-{2-[(tert-butoxycarbonyl)amino]ethyl}-4-chloro-1,6-dihydro-2H-furo[3,2-e]indole-7-carboxylic acid and 7-{2-[(tert-butoxycarbonyl)amino]ethyl}-8-chloro-3,5-dihydro-2H-furo[2,3-f]indole-6-carboxylic acid, and diisopropylethylamine (4.16 mL), methylamine hydrochloride (988 mg), and N,N-dimethyl formamide (37.0 mL) was added 2-(7-aza-1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (2.77 g), followed by stirring at room temperature overnight. To the mixture was added water under ice-cooling, and the precipitated solid was collected by filtration and dried under reduced pressure to obtain a yellowish brown solid. This was purified by silica gel column chromatography (toluene:chloroform:methanol=5:4:0 to toluene:chloroform:methanol=50:40:6) to obtain tert-butyl {2-[4-chloro-7-(methylcarbamoyl)-1,6-dihydro-2H-furo[3,2-e]indol-8-yl]ethyl}carbamate (213 mg) of a high-polarity fraction as a compound of Preparation Example 26. Further, the low-polarity fraction was concentrated under reduced pressure and the obtained residue was solidified with ethanol to obtain a yellow solid of tert-butyl {2-[8-chloro-6-(methylcarbamoyl)-3,5-dihydro-2H-furo[2,3-f]indol-7-yl]ethyl}carbamate (750 mg) as a compound of Preparation Example 66 as shown in the table below.

Provenance & Evidence