Sulfuric Acid → Ammonium Hydroxide

Participants

Reaction Steps

A solution of 0.200 g (0.78 mmol) of [(7SR,9aSR)-2-(pyrimidin-2-yl)-2,3,4,6,7,8,9,9a-octahydro-1H-pyrido[1,2-a]pyrazin-7-yl]acetonitrile in 4 mL of dry THF was treated with 4.3 mg (0.03 mmol) of cuprous bromide and 0.85 mL (0.85 mmol) of 4-fluorophenyl magnesium bromide (1M in THF), and the mixture was refluxed for 48 h. The mixture was cooled to room temperature, 0.75 mL of water was added carefully followed by 3.5 mL of 15% sulfuric acid. The mixture was refluxed for 24 h. The reaction was cooled to room temperature, and 10% sodium carbonate solution was added until gas evolution ceased. Ethyl ether (10 mL) was added, the layers were separated, and the aqueous phase was extracted with ethyl ether (2×10 mL). The combined organics were dried (sodium sulfate), filtered and evaporated. Purification by flash silica gel chromatography with ethyl acetate:hexane:methanol:conc. ammonium hydroxide (1:1:0.01:0.01) gave 30 mg of the title compound. 13C NMR (CDCl3): d 25.1, 28.3, 29.9, 40.2, 43.7, 49.1, 54.8, 59.1, 61.1, 109.7, 115.4, 115.7, 130.8, 130.9, 134.0, 157.7, 161.5, 164.0, 167.4. HRMS calcd for C20H23FN4O: 354.1856, found: 354.1847.

Provenance & Evidence