Oxalic Acid → HCID 20081800, compound

Participants

Reaction Conditions

Reaction Steps

778 mg (3.2 mmol) of diethyl [2-(cyclohexylamino)vinyl]-phosphate in 3 ml of tetrahydrofuran are added under a nitrogen atmosphere to 75.5 mg (3.2 mmol) of sodium hydride in 3 ml of absolute tetrahydrofuran during the course of 15 minutes at 0° C., the mixture is stirred for 15 minutes at 0° C. and a solution of 0.6 g (2.6 mmol) of the compound from Example 30 in 3 ml of acetonitrile/3 ml of dimethylformamide is added dropwise. After stirring for 1 h at 0° C. and 30 minutes at 25° C., the mixture is hydrolyzed using 50 ml of water, washed with ether (3×50 ml), and the organic phase is dried, concentrated in vacuo, taken up in 8 ml of toluene and stirred with 1.2 g (13.5 mmol) of oxalic acid/20 ml of water for 1.5 h at 60° C.-80° C. under a nitrogen atmosphere. After cooling, the mixture is adjusted to pH 10 using 2N sodium hydroxide solution and washed four times with ether, and the ether phase is dried, concentrated in vacuo and chromatographed over 100 g of silica gel using dichloromethane/methanol 30:1.

Provenance & Evidence