Sodium periodate → 3-(2-Chloro-pyridin-3-y)-6-fluoro-3,4-dihydro-quinazolin-4-one-2-carboxaldehyde

Participants

Reaction Steps

To a mixture of sodium periodate (1.9 g, 8.7 mmol) in tetrahydrofuran (10 mL) and aqueous pH 7 buffer (15 mL) was added 3-(2-chloro-pyridin-3-yl)-6-fluoro-2-(2-dimethylamino-vinyl)-3,4-dihydro-quinazolin-4-one (1.0 g, 2.90 mmol) all at once. The reaction was stirred for 1 hour. The precipitate was collected, washed well with water and dried under a nitrogen stream to afford 0.863 g (92%) of 3-(2-chloro-pyridin-3-yl)-6-fluoro-3,4-dihydro-quinazolin-4-one-2-carboxaldehyde as a yellow solid which was about a 25:1 mixture of hydrate to free aldehyde. The product was characterized as follows: mp 160-164° C.; 1H NMR (DMSOd6) δ (hydrate) 8.51 (dd, J=2, 5 Hz, 1 H), 8.08 (dd, J=2, 8 Hz, 1 H), 7.87-7.78 (m, 3 H), 7.60 (dd, J=5, 8 Hz, 1 H), 6.64 [ABq, Dn1-3=18 Hz, J=7 Hz, 2 H (hydrate OHs], 5.27 [br s, 1 H (hydrate methine CH]. Addition of D2O to the NMR sample caused the multiplet at 6.64 ppm to disappear and sharpened up the singlet at 5.27 ppm. The presence of free aldehyde was demonstrated by a minor singlet at 9.51 ppm.

Provenance & Evidence