Sodium Dithionite → HCID 21946139, compound

Participants

Reaction Steps

Methyl ester (10a) (22.83 g, 72.4 mmol) was dissolved in 400 ml of 0.5 M aqueous sodium hydroxide and the solution was stirred for 1 h. A solution of sodium dithionite solution (200 ml, 100 mmol) was added and reaction mixture was stirred for additional 15 minutes. To precipitate the product 3 M hydrochloric acid (80 ml) was carefully added and resultant suspension was stirred for 10 min and centrifuged. The supernatant was decanted and the residue was re-suspended in ˜800 ml of water and centrifuged again. This operation was repeated one more time. Final supernatant had pH of 3-4. The centrifuged material was dried under vacuum overnight at 40° C. to afford 14.12 g (68%) of desired product (11a) as a brown solid. 1H NMR (CD3OD, +40° C.): δ 7.64 (d, J=9.0 Hz, 1H), 7.39 (s, 1H), 6.89 (d, J=9.0 Hz, 1H), 6.74 (s, 1H), 6.34 (s, 1H), 2.63 (m, 2H), 2.51 (m, 2H).

Provenance & Evidence