Methyl tyrosinate hydrochloride → Tyr(3-tBu)-OMe

To a solution of Tyr-OMe.HCl (500 g, 2.16 mol) in tert-butyl acetate (4500 ml), 70% HCl4 (278 ml, 3.24 mol) was added and stirred for 4.5 days at room temperature. The reaction mixture was evaporated under reduced pressure; the thus obtained residue was dissolved in ethyl acetate, poured into a saturated aqueous NaHCO3 solution and stirred. The organic layer was collected and washed with a saturated aqueous NaHCO3 solution and saturated brine, dried over anhydrous magnesium sulfate and evaporated to remove the solvent under reduced pressure. The thus obtained residue was mixed with ether (950 ml) and at room temperature, stirred overnight. The thus precipitated crystals were collected by filtration to give Tyr(3-tBu)-OMe (242 g, 45%).

1. customThe reaction mixture was evaporated under reduced pressure
2. dissolutionthe thus obtained residue was dissolved in ethyl acetate
3. additionpoured into a saturated aqueous NaHCO3 solution
4. stirringstirred
5. customThe organic layer was collected
6. washwashed with a saturated aqueous NaHCO3 solution and saturated brine
7. dry with materialdried over anhydrous magnesium sulfate
8. customevaporated
9. customto remove the solvent under reduced pressure
10. additionThe thus obtained residue was mixed with ether (950 ml) and at room temperature
11. stirringstirred overnight
12. filtrationThe thus precipitated crystals were collected by filtration

ORD record

ord-aa5a6db7e9e746e78686fddd87fcf39f

Source dataset

uspto-grants-2009_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07553969B1