Tetrabutylammonium Fluoride → (S)-3-methyl-3-(4-methyl-3-oxo-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylamino)-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of (S)-3-methyl-3-[4-methyl-3-oxo-2-(2-trimethylsilanyl-ethoxymethyl)-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylamino]-pyrrolidine-1-carboxylic acid tert-butyl ester (1.1 g, 2.016 mmol) in a solution of TBAF in THF (1 M, 20 mL, 20 mmoL) was stirred at 80° C. overnight. The reaction mixture was cooled to ambient temperature and diluted with water (25 mL). The aqueous solution was extracted with EtOAc (3×25 mL). The combined organic phase was washed with brine (10 mL), dried over sodium sulfate and filtered. The filtrate was concentrate in vacuo to give the residue, which was purified by column chromatography on silica gel (eluting with 10% EtOAc in petroleum) to give (S)-3-methyl-3-(4-methyl-3-oxo-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylamino)-pyrrolidine-1-carboxylic acid tert-butyl ester (0.45 g, 54%). 1H NMR (400 MHz, CDCl3) δ 8.19-8.05 (m, 1H), 6.94-6.77 (m, 1H), 6.53-6.23 (m, 2H), 4.74-4.46 (m, 3H), 3.62-3.30 (m, 4H), 2.32-2.17 (m, 1H), 2.00-1.86 (m, 1H), 1.59-1.44 (m, 15H).

Provenance & Evidence