ChemicalBook CAS DataBase List Boc-L-Tyrosine methyl ester

Boc-L-Tyrosine methyl ester synthesis

11synthesis methods

Product Name:Boc-L-Tyrosine methyl ester
CAS Number:4326-36-7
Molecular formula:C15H21NO5
Molecular Weight:295.33

67-56-1 Synthesis

67-56-1
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$7.29/5ml-f

24424-99-5 Synthesis

24424-99-5
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$13.50/25G

60-18-4 Synthesis

60-18-4
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$15.00/25g

4326-36-7
352 suppliers
$6.00/5g

Yield:4326-36-7 100%

Reaction Conditions:

Stage #1:methanol;L-tyrosine with thionyl chloride for 3 h;Inert atmosphere;Heating;
Stage #2:di-tert-butyl dicarbonate with triethylamine in methanol for 20 h;Inert atmosphere;

Steps:

1.1 Methyl (2S)-2-[(tert-butoxycarbonyl)amino]-3-(4-hydroxyphenyl)propanoate 10a
To the suspension of (S)-tyrosine (5.00 g, 27.60 mmol) in dry methanol (100 mL), thionyl chloride (10 mL) was added dropwise.
Reaction mixture was heated under argon atmosphere for 3 h and then evaporated.
Dry methanol (100 mL), Boc₂O (9.44 g, 43.30 mmol) and triethylamine (9.10 g, 90.10 mmol) were added, the mixture was stirred under an argon atmosphere for 20 h and finally, solvents were evaporated.
Residue was diluted with water (50 mL), pH was adjusted to 4 by 2 M aqueous HCl and the mixture was extracted with ethyl acetate (5 * 50 mL).
Collected organic layers were washed with brine, dried over MgSO₄ and evaporated.
After column chromatography (CHCl₃/MeOH 100:3), 8.15 g (quant.) of 10a was obtained, mp 105.4-107.5 °C, [α]_D²⁵ = +4.0 (c 0.379, MeOH) [ref.
²⁷
mp 102-104 °C, [α]_D²⁰ = +8.8 (c 1.7, MeOH)].
¹H NMR (300 MHz, CDCl₃): δ = 1.41 (s, 9H, (CH₃)₃), 2.87-3.08 (m, 2H, CH₂Ar), 3.71 (s, 3H, CH₃O), 4.47-4.60 (m, 1H, CHN), 5.03 (d, J = 7.9 Hz, 1H, NH), 6.10 (s, 1H, OH), 6.72 (d, J = 8.2 Hz, 2H, ArH), 6.95 (d, J = 8.5 Hz, 2H, ArH) ppm. ¹³C NMR (75 MHz, CDCl₃): δ = 28.5, 37.8, 52.5, 54.9, 80.5, 115.7, 127.7, 130.6, 155.4, 155.6, 172.9 ppm.