ChemicalBook CAS DataBase List 4'-carbamoyl N-Boc-2',6'-dimethyl-L-phenylalanine methyl ester

4'-carbamoyl N-Boc-2',6'-dimethyl-L-phenylalanine methyl ester synthesis

12synthesis methods

Product Name:4'-carbamoyl N-Boc-2',6'-dimethyl-L-phenylalanine methyl ester
CAS Number:623950-05-0
Molecular formula:C18H26N2O5
Molecular Weight:350.41

methyl (S)-2-((tert-butoxycarbonyl)amino)-3-(2,6-dimethyl-4-(((trifluoromethyl)sulfonyl)oxy)phenyl)propanoate

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4'-carbamoyl N-Boc-2',6'-dimethyl-L-phenylalanine methyl ester

623950-05-0
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Yield:623950-05-0 100%

Reaction Conditions:

Stage #1: methyl (S)-2-((tert-butoxycarbonyl)amino)-3-(2,6-dimethyl-4-(((trifluoromethyl)sulfonyl)oxy)phenyl)propanoate;3-oxobenzo[d]isothiazole-2(3H)-carbaldehyde 1,1-dioxidewith potassium fluoride;palladium diacetate;4,5-bis(diphenylphosphino)-9,9-dimethylxanthene in N,N-dimethyl-formamide at 80 - 85; for 0.16 h;
Stage #2: with ammonia;triethylamine at 0 - 5;Reagent/catalyst;

Steps:

2 Preparation of methyl (S)-2-((tert-butoxycarbonyl)amino)-3-(4-carbamoyl-2,6- dimethylphenyl)propanoate, compound of formula (5) wherein n is 2, R¹and R²are methyl, R⁵and R¹⁰are H, and Pg is tert- butyloxycarbonyl.

This example is representative of operations e.1 ) and e.2) of the process of the invention.The oily residue prepared as described in example 1 (6.0 mmol theoretical) was dissolved in /V,/V-dimethyl formamide (56 ml_). /V-formylsaccarin (1 .90 g, 9.0 mmol), Xantphos (0.16 g, 0.3 mmol), potassium fluoride (8.70 g, 15.0 mmol), and palladium (II) acetate (0.04 g, 0.2 mmol) were added. The resulting mixture was subjected to 3 cycles of vacuum/nitrogen, then maintained under stirring at 80-85 °C until complete conversion (about 16 hours). The reaction was cooled to 20-25 °C and subjected to 3 cycles of vacuum nitrogen (in order to remove the formed carbon monoxide) then it was further cooled to 0-5 °C and triethylamine (2.43 g, 24.0 mmol) and ammonia (0.15 g, 9.0 mmol) were added thereto. When the conversion was complete, the mixture was evaporated under reduced pressure in order to remove most of L/,/V-di methyl formamide, then water (42 ml.) and isopropyl acetate (8.5 ml.) were added. The mixture was heated to 45 °C, then filtered on a pad of celite and charcoal. The phases were separated, then a 5% (w/w) aqueous solution of sodium carbonate (4.80 g) was added to the organic phases. After having separated the resulting layers, the organic phase is concentrated under reduced pressure so as to obtain an oily residue (2.85 g, quantitative yield).

References:

WO2019/197274,2019,A1 Location in patent:Page/Page column 31-32; 36-37

864825-84-3 Synthesis