Diisopropylethylamine → HCID 178502530, compound

N,N-Diisopropylethylamine (497 μl) and ethylisocyanatoformate (177 μl) were added to a stirred solution of trans-4-(2,4-bis{[tert-butyl(dimethyl)silyl]oxy}phenyl)cyclohexanol (250 mg) in anhydrous dimethylformamide (2 ml). After 120 hr at 50° C., the reaction mixture was partitioned between ethyl acetate (50 ml) and water (50 ml). The aqueous layer was extracted with ethyl acetate (2×50 ml). The combined organic extracts were washed with brine (50 ml), dried over magnesium sulfate and evaporated in vacuo. The residue was dissolved in methanol (10 ml) and was stirred with fluoride resin (300 mg) for 16 hr at room temperature. The suspension was filtered through a pad of celite, which was washed well with methanol. The combined filtrates were concentrated in vacuo and the residue was purified using flash column chromatography (SiO2, ethyl acetate/petrol, 1:3 v/v) and then preparative HPLC to give the title compound (4 mg, 2%) as a pale yellow gum. δH (CD3OD) 1.20-1.40 (4H, m), 1.55 (3H, t), 1.80-1.90 (2H, m), 2.00-2.18 (2H, m), 2.72-2.82 (1H, m), 4.20 (2H, q), 6.20-6.25 (2H, m), 6.84 (1H, d); m/z(ES−) 322 (M−H−).

1. customthe reaction mixture was partitioned between ethyl acetate (50 ml) and water (50 ml)
2. extractionThe aqueous layer was extracted with ethyl acetate (2×50 ml)
3. washThe combined organic extracts were washed with brine (50 ml)
4. dry with materialdried over magnesium sulfate
5. customevaporated in vacuo
6. dissolutionThe residue was dissolved in methanol (10 ml)
7. filtrationThe suspension was filtered through a pad of celite, which
8. washwas washed well with methanol
9. concentrationThe combined filtrates were concentrated in vacuo
10. customthe residue was purified

ORD record

ord-361cd316362341f0a93740491206ec0e

Source dataset

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06541473B2