Sulfuric Acid → HCID 68612479, compound

HRID 1993123Notes

Reaction equation

[NH:1]([C:15]([O:17][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:16])[C@H:2]([C:11]([O:13][CH3:14])=[O:12])[CH2:3][C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][CH:5]=1.OS(O)(=O)=O>C(Cl)Cl>[CH3:14][O:13][C:11](=[O:12])[CH:2]([NH:1][C:15]([O:17][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:16])[CH2:3][C:4]1[CH:5]=[CH:6][C:7]([O:10][C:4]([CH3:9])([CH3:5])[CH3:3])=[CH:8][CH:9]=1

Participants

Conditions

Temperature: 0 °C

Procedure

H-D-Tyr-O-me hydrochloride 2.1 (25 g, 107.7 mmol) is dissolved in methylene chloride (150 mL) and aqueous sodium bicarbonate (22 g in 150 mL water), and then cooled to 0° C. To this resulting solution benzyl chloroformate (20 g, 118 mmol) is slowly added. After complete addition, the resulting solution is warmed to room temperature, and is then stirred for 2 h. The organic phase is separated, dried over Na2SO4, and concentrated under reduced pressure, to give the crude carbamate 2.2 (35 g). The crude CBZ-Tyr-OMe product is dissolved in methylene chloride (300 mL) containing concentrated H2SO4. Isobutene is bubbled though the solution for 6 h. The reaction is then cooled to 0° C., and neutralized with saturated NaHCO3 aqueous solution. The organic phase is separated, dried, concentrated under reduced pressure, and purified by silica gel column chromatography to afford the tert-butyl ether 2.3 (25.7 g, 62%).

Workup

customIsobutene is bubbled though the solution for 6 h
customThe organic phase is separated
customdried
concentrationconcentrated under reduced pressure
custompurified by silica gel column chromatography

Sources & evidence

ORD record: ord-13fe3210d6a74112b109acd79734f875
Source dataset: uspto-grants-2010_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07649015B2

Reaction notes

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