Pyridine → HCID 71582576, compound

Temperature

60 °C

To this solution, DMAc (200 mL), pyridine (145 g, 2.5 eq.), DMAP (8.97 g, 0.10 eq.), and succinic anhydride (73.5 g, 1.0 eq.) were added in this order, and the mixture was stirred at 60° C. for 8 hours. The reaction mixture was cooled to room temperature and then washed with water (600 mL) to obtain an organic layer. The aqueous layer was subjected to extraction twice with TBME (200 mL for each). The combined organic layers were washed with 2 M hydrochloric acid (1.0 L), then further washed twice with a 5% aqueous sodium bicarbonate solution (1.0 L for each), and concentrated. The concentrated residue was diluted with hexane (500 mL), washed with a 5% aqueous sodium bicarbonate solution (500 mL) and 20% saline (200 mL) in this order, and then concentrated. The residue was distilled (pressure: 2.8 to 3.0 kPa, distillation temperature: 102 to 104° C.) to obtain (1R,5S)-3-ethylbicyclo[3.2.0]hept-3-en-6-one (41.3 g, yield: 41%, 97.7% ee).

1. temperatureThe reaction mixture was cooled to room temperature
2. washwashed with water (600 mL)
3. customto obtain an organic layer
4. extractionThe aqueous layer was subjected to extraction twice with TBME (200 mL for each)
5. washThe combined organic layers were washed with 2 M hydrochloric acid (1.0 L)
6. washfurther washed twice with a 5% aqueous sodium bicarbonate solution (1.0 L for each), and
7. concentrationconcentrated
8. additionThe concentrated residue was diluted with hexane (500 mL)
9. washwashed with a 5% aqueous sodium bicarbonate solution (500 mL) and 20% saline (200 mL) in this order
10. concentrationconcentrated
11. distillationThe residue was distilled
12. distillation(pressure: 2.8 to 3.0 kPa, distillation temperature: 102 to 104° C.)

ORD record

ord-459f48f1b6b54daaa196abc369c8042e

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09394235B2