HCID 54363709, compound → HCID 54401458, compound

Participants

Reaction Steps

To 0.506 g of the above-obtained 2-[(O-acetyl-N-trifluoroacetyl-D-seryl)amino]methylthiazole was added 10 ml of phosphorus oxychloride. The mixture was refluxed for 5 hours, cooled to room temperature, and then concentrated to dryness under reduced pressure. To the residue was added 50 ml of methylene chloride, and the mixture was thoroughly stirred. To this was added 30 ml of a saturated aqueous solution of sodium hydrogencarbonate with ice-cooling, and the mixture was stirred for an additional 30 minutes. Insoluble matters were removed by filtration. The organic layer was separated, and the aqueous layer was extracted with 30 ml of methylene chloride. The combined organic layers were dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by flash column chromatography using silica gel, eluting with a 2:1 mixture of ethyl acetate and hexane to give 0.319 g (yield 67%) of 5-[(R)-2-acetoxy-1-(trifluoroacetyl-amino)ethyl]imidazo[5,1-b]thiazole. NMR (CDCl3) d: 2.08 (3H, s), 4.53 (1H, dd, J=11.6 Hz, 5.3 Hz), 4.57 (1H, dd, J=11.6 Hz, 7.8 Hz), 5.67 (1H, td, J=7.8 Hz, 5.3 Hz), 6.92 (1H, d, J=4.3 Hz), 7.05 (1H, s), 7.56 (1H, d, J=4.3 Hz), 7.64-7.74 (1H, br)

Provenance & Evidence