Hydrochloric Acid → (+/-)-6-Formyl-chroman-2-carboxylic acid

Temperature

-30 °C

A solution of the compound from Example 9 (11.5 g, 64.5 mmol) in dichloromethane (60 mL) was added to a cooled (−10° C.) mixture of aluminum chloride (21.5 g, 161 mmol) in dichloromethane (30 mL). The mixture was cooled to −30° C. for 20 minutes and dichloromethyl methyl ether (11.7 mL, 129 mmol) was added dropwise over one hour. After an additional 45 minutes the mixture was poured into a mixture of ice (325 mL) and concentrated HCl (5 mL). The mixture was filtered and the filtrate removed. The collected solids were dissolved in tetrahydrofuran. The tetrahydrofuran solution was dried (MgSO4) and concentrated to give a solid. The solid was washed with dichloromethane (3×25 mL) and dried in vacuo at room temperature to give a light pink solid (4.34 g, 33%). 1H NMR (300 MHz, DMSO-d6) δ13.17 (br s, 1H), 9.81 (s, 1H), 7.64 (m, 2H), 6.99 (d, J=9.2 Hz, 1H), 4.94 (t, J=5.0 Hz, 1H), 2.87 (m, 1H), 2.68 (m, 1H), 2.14 (m, 2H); MS (FAB) m/z 207 (MH+).

1. temperaturea cooled
2. filtrationThe mixture was filtered
3. customthe filtrate removed
4. dissolutionThe collected solids were dissolved in tetrahydrofuran
5. dry with materialThe tetrahydrofuran solution was dried (MgSO4)
6. concentrationconcentrated
7. customto give a solid
8. washThe solid was washed with dichloromethane (3×25 mL)
9. customdried in vacuo at room temperature

ORD record

ord-821a0877de1c4811aee2cea68e2cb957

Source dataset

uspto-grants-2002_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06469031B1