Phosphoric Acid → HCID 55265943, compound

Temperature

-44 °C

A three neck flask fitted with an internal thermometer containing thieno[3,2-c]pyridine (5.0 g, 37 mmol, 1 equivalent) was evacuated and then filled with a nitrogen gas atmosphere. THF (60 mL) was added and the solution was cooled to −44° C. (CH3CN/dry ice). n-Butyllithium (1.6M/hexane, 25 mL, 41 mmol, 1.1 equivalents) was added over 10 minutes, while maintaining the internal temperature at or below −33° C. The reaction was stirred at −33 to −45° C. for 60 minutes. Triisopropyl borate (10.2 mL, 44 mmol, 1.2 equivalents) was added and the cooling bath removed. The reaction was allowed to proceed for 105 minutes. Then 3.0 mL phosphoric acid (85% aqueous, 3.0 mL, 44 mmol, 1.2 equivalents) was added. A yellow solid formed, which was diluted with water and Et2O (about 150 mL each). A yellow solid was collected by filtration and was dried by suction overnight (5.05 g). Analytical Data: 1H NMR (400 MHz, METHANOL-d4) β ppm 7.95 (1H, s), 8.09 (1H, d, J=5.9 Hz), 8.34 (1H, d, J=6.1 Hz), 9.09 (1H, s). MS (APCI, M+1) 180.1. Microanalysis for C7H6BNSO2.H3PO4: calculated C, 30.35; H, 3.27; N, 5.06; P, 11.18. Found: C, 41.12; H, 3.19; N, 6.53; P, 0.68%.

1. customA three neck flask fitted with an internal thermometer
2. customwas evacuated
3. additionfilled with a nitrogen gas atmosphere
4. additionTHF (60 mL) was added
5. temperaturewhile maintaining the internal temperature at or below −33° C
6. customthe cooling bath removed
7. waitto proceed for 105 minutes
8. customA yellow solid formed
9. filtrationA yellow solid was collected by filtration
10. customwas dried by suction overnight (5.05 g)

ORD record

ord-6d260a55082f49baa9fb393a75850bb9

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09260450B2