Sodium Hydroxide → Furo[3,2-C]pyridine-6-carboxylic acid

Methyl furo[3,2-c]pyridine-6-carboxylate (1.55 g, 8.74 mmol) is dissolved in MeOH (30 mL) and H2O (15 mL), treated with 3 N NaOH (6.4 mL) and stirred at rt for 7 h. The mixture is concentrated to dryness, dissolved in H2O (10 mL) and acidified to pH 2 with concentrated HCl. The solution is concentrated to dryness, suspended in a smaller amount of water (7 mL) and the resulting solid collected via filtration (lot A). The filtrate is concentrated, triturated with water (3 mL) and the resulting solid collected via filtration (lot B). The filtrate from lot B is concentrated and carried on without further purification as an acid/salt mixture (lot C). Both lots A and B are dried in a vacuum oven at 50° C. for 18 h to afford 690 mg (48%) for lot A, 591 mg (42%) for lot B and 130 mg (10%) of furo[3,2-c]pyridine-6-carboxylic acid as yellow solids. MS (CI) m/z: 164 (M+H+).

1. concentrationThe mixture is concentrated to dryness
2. dissolutiondissolved in H2O (10 mL)
3. concentrationThe solution is concentrated to dryness
4. filtrationthe resulting solid collected via filtration (lot A)
5. concentrationThe filtrate is concentrated
6. customtriturated with water (3 mL)
7. filtrationthe resulting solid collected via filtration (lot B)
8. concentrationThe filtrate from lot B is concentrated
9. customcarried on without further purification as an acid/salt mixture (lot C)
10. customBoth lots A and B are dried in a vacuum oven at 50° C. for 18 h

ORD-Eintrag

ord-7d5b1febf14447c299cb2d1acfa15930

Quelldatensatz

uspto-grants-2006_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07067515B2