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
369 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.