Tetrabutylammonium Fluoride → 3-(4-Methyl-3-oxo-7-trifluoromethyl-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylmethyl)-azetidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-[4-methyl-3-oxo-7-trifluoromethyl-2-(2-trimethylsilanyl-ethoxymethyl)-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylmethyl]-azetidine-1-carboxylic acid tert-butyl ester (0.052 g, 0.08 mmol) in THF (1 mL) was added TBAF (1M in THF, 1 mL) and the solution was heated to 80° C. for 14 h. The reaction mixture was cooled to ambient temperature and the solvent was removed in vacuo. The residue was partioned between EtOAc (5 mL) and water (5 mL). The aqueous phase was extracted with EtOAc (3×10 mL). The combined organic portion was dried over anhydrous Na2SO4, filtered and concentrated in vacuo. The residue was purified by preparative TLC (eluting with 50% EtOAc in petroleum ether) to give 3-(4-methyl-3-oxo-7-trifluoromethyl-2,3,4,10-tetrahydro-9-oxa-1,2,4a-triaza-phenanthren-6-ylmethyl)-azetidine-1-carboxylic acid tert-butyl ester (0.019 g, 44%). LC/MS (Table 1, Method 2) Rt=1.230 min.; MS m/z: 477 [M+23]+.

Provenance & Evidence