Sodium Hydroxide → 2,2-Dimethylchroman-6-carboxylic acid

Temperature

65 °C

A mixture of 5.8 g (28.4 mmol) of 2,2-dimethyl-6-acetylchroman (Compound 57), 75 ml of dioxane, 300 ml of 10% sodium hypochlorite solution and 50 ml of a 20% solution of NaOH in water was heated at 65° C. for 0.5 hour. The mixture was then treated with another 200 ml of 10% sodium hypochlorite solution and then heated at 65° C. for a further 65 hours. The mixture was cooled to room temperature and washed with ether. The aqueous layer was then treated with sodium metabisulphite solution until it was negative to the potassium iodide-starch test. The aqueous solution was then acidified to pH=4 with dilute H2SO4 and stored in the refrigerator for 48 hours. The solution was then diluted with water and extracted with ether. The ether layers were combined and washed with saturated NaCl solution and then dried (MgSO4). The solution was filtered and the solvent was removed in-vacuo to give the title compound as a white solid. PMR (CDCl3): & 1.36 (6H, s), 1.84 (2H, t, J~6.8 Hz), 6.81 (1H, d, J~8.4 Hz), 7.82-7.89 (2H, m). MS exact mass, m/e 206.0942 (calcd. for C12H14o3 206.0943).

1. temperatureheated at 65° C. for a further 65 hours
2. temperatureThe mixture was cooled to room temperature
3. washwashed with ether
4. additionThe aqueous layer was then treated with sodium metabisulphite solution until it
5. additionThe solution was then diluted with water
6. extractionextracted with ether
7. washwashed with saturated NaCl solution
8. dry with materialdried (MgSO4)
9. filtrationThe solution was filtered
10. customthe solvent was removed in-vacuo

ORD record

ord-b1a5ec02614345f69f37a100a0eb9f2d

Source dataset

uspto-grants-1991_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05006550