2-((3aR,4S,6R,6aS)-6-amino-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-yloxy)ethanol L-tataric acid

White to off-white powder

2-[[(3aR,4S,6R,6aS)-6-aminotetrahydro-2,2-dimethyl-4H-cyclopenta-1,3-dioxol-4-yl]oxy]-Ethanol (2R,3R)-2,3-dihydroxybutanedioate is a useful building block, most frequently used in the preparation of the antithrombotic agent Ticagrelor.

Put 50g of benzyl ((3aS,4R,6S,6aR)-6-(2-hydroxyethoxy)-2,2-dimethyltetrahydro-4H-cyclopenta[d][1,3]dioxol-4-yl)carbamate and 250 mL of methanol into a 1L four-necked flask 1.Add 10 g of 10% palladium carbon and 22.4 g of ammonium formate to bottle 1 at 20-30°C. After the addition, the temperature is raised to 40-50°C, and the reaction is stirred for 10 hours and filtered with suction. The filtrate was transferred to a 1L four-neck flask 2, and the temperature was raised to 40-50°C again. 21.4g L-tartaric acid was added to batches 2 while stirring. Then, continue to stir the reaction for 1 hour, slowly lower the temperature to 10-20°C, and stir the reaction for 2 hours, and a large number of white solids can be seen to precipitate. Continue to lower the temperature to 0-10°C and react for 0.5h, then suction filter and wash the filter cake once with 50mL ethanol. The filter cake was dried under reduced pressure at 40° C. for 4 hours to obtain 45.7 g of white powdery solid 2-((3aR,4S,6R,6aS)-6-amino-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-yloxy)ethanol L-tataric acid with a yield of 87.47%.

2-((3aR,4S,6R,6aS)-6-amino-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxol-4-yloxy)ethanol L-tataric acid could be used to synthesis 2-[((3aR,4S,6R,6aS)-6-{[5-nitro-6-chloro-2-(propylthio)- 4-pyrimidinyl]amino}-2,2-dimethyltetrahydro-3aH-cyclopenta[d][1,3]dioxoI-4-yl)oxy]-1-ethanol.