Ammonium Chloride → HCID 58478817, compound

To a suspension of (methoxymethyl) triphenylphosphonium chloride (889 mg, 2.6 mmol) in anhydrous THF (10 mL) is added slowly to a solution of potassium tert butoxide in tBuOH (2.4 mL of a 1.0 M solution in tBuOH, 2.4 mmol) under an argon atmosphere. The brown reaction mixture is stirred at room temperature for 30 min, cooled to 0° C. and treated with 5-oxo-5,7-dihydro-furo[3,4-b]pyridine-2-carbaldehyde (326 mg, 2.0 mmol) in one portion. The dark brown reaction mixture is stirred at room temperature for 3 h and then poured into saturated aqueous NH4Cl solution (30 mL). The reaction mixture is extracted with EtOAc (2×). The combined organic extracts are dried Na2SO4, filtered and concentrated. The residue is purified by chromatography (silica gel, EtOAc/hexane) to give the higher Rf E-isomer, E-2-(2-Methoxy-vinyl)-7H-furo[3,4-b]pyridin-5-one (111 mg, 0.58 mmol) and lower Rf Z-isomer, Z-2-(2-Methoxy-vinyl)-7H-furo[3,4-b]pyridin-5-one (61 mg, 0.32 mmol). Total yield is 45%.

1. temperaturecooled to 0° C.
2. stirringThe dark brown reaction mixture is stirred at room temperature for 3 h
3. extractionThe reaction mixture is extracted with EtOAc (2×)
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue is purified by chromatography (silica gel, EtOAc/hexane)

ORD record

ord-da19f07b7d9446908f3a7418087a73ca

Source dataset

uspto-grants-2011_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07977351B2