tert-Butanol → tert-Butyl-2-(4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl)acetate

In anhydrous conditions, Tetrac (30.0 g, 40.1 mmol, 1.0 eq.) was dissolved in anhydrous dioxane (200 mL). Tert-butyl alcohol (11.4 mL, 120.3 mmol, 3.0 eq.) and 4-dimethylaminopyridine (3.9 g, 32.1 mmol, 0.8 eq.) were then added. The solution was stirred and dicyclohexylcarbodiimide (9.1 g, 44.1 mmol, 1.1 eq.) was added over a 5 minutes period. The mixture was stirred for 3 hours at room temperature. The cyclohexylurea that has precipitated was removed by filtration through a fritted Büchner funnel, and the filtrate was washed with 10% potassium bicarbonate solution (2×100 mL). During this procedure, some additional cyclohexylurea precipitated and was removed by filtration of both layers to facilitate their separation. The organic solution was then dried over magnesium sulfate, filtered and then evaporated with a rotary evaporator to obtain the crude product as a yellow powder which was purified by column chromatography (DCM/cyclohexane 90/10) to yield tert-butyl-2-(4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl)acetate (3.2 g, 4.0 mmol) as a solid.

1. stirringThe mixture was stirred for 3 hours at room temperature
2. customThe cyclohexylurea that has precipitated
3. customwas removed by filtration through a fritted Büchner funnel
4. washthe filtrate was washed with 10% potassium bicarbonate solution (2×100 mL)
5. customDuring this procedure, some additional cyclohexylurea precipitated
6. customwas removed by filtration of both layers
7. customtheir separation
8. dry with materialThe organic solution was then dried over magnesium sulfate
9. filtrationfiltered
10. customevaporated with a rotary evaporator
11. customto obtain the crude product as a yellow powder which
12. customwas purified by column chromatography (DCM/cyclohexane 90/10)

ORD record

ord-d832ae7f6dd2400a86b6fb17285cbe93

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09220788B2