Mannitol → Mannitol monocarbonate

Temperature

0 °C

To a solution of astaxanthin 2E (0.100 g, 0.168 mmol) in DCM (4 mL) at 0° C. was added DIPEA (0.585 mL, 3.36 mmol), and 1,2,2,2-tetrachloroethyl chloroformate (0.103 mL, 0.672 mmol). The reaction mixture was stirred at 0° C. for 2 hours, then at room temperature for 1.5 hours, at which time (D)-mannitol (0.3060 g, 1.68 mmol), DMF (3 mL), and DMAP (0.2052 g, 1.68 mmol) were added to the reaction. The reaction mixture was stirred at room temperature for 24 hours, at which time the reaction was diluted with DCM, quenched with brine (20 mL), and then extracted with DCM. The combined organic layers were concentrated to yield mannitol monocarbonate (LVII) (10.19%) HPLC retention time: 9.474 min., 10.19% (AUC); LRMS (ESI) m/z (relative intensity): 827 (M++Na) (50), 804 (M+) (25), 725 (58), 613 (100), and astaxanthin 2E (53.73%).

1. waitat room temperature for 1.5 hours
2. stirringThe reaction mixture was stirred at room temperature for 24 hours, at which time the reaction
3. customquenched with brine (20 mL)
4. extractionextracted with DCM
5. concentrationThe combined organic layers were concentrated

ORD record

ord-1d0f8210da6d4ad386a59e203537d222

Source dataset

uspto-grants-2006_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07145025B2