ChemicalBook CAS DataBase List tert-Butyl (2-(2,2-dimethyl-4H-benzo[d][1,3]dioxin-6-yl)-2-oxoethyl)carbamate

tert-Butyl (2-(2,2-dimethyl-4H-benzo[d][1,3]dioxin-6-yl)-2-oxoethyl)carbamate synthesis

8synthesis methods

Product Name:tert-Butyl (2-(2,2-dimethyl-4H-benzo[d][1,3]dioxin-6-yl)-2-oxoethyl)carbamate
CAS Number:452339-71-8
Molecular formula:C17H23NO5
Molecular Weight:321.37

Trifluoroacetic acid (10.2 mL) was added to di-(tert-butyl)2-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl) -2-oxoethyliminodicarbonic acid at 20°C (46.37 g) in a stirred solution of dichloromethane (500 mL) and stirred for 4 hours. Aqueous sodium hydroxide solution (0.5 M, 400 mL) was added to the reaction solution, stirred for half an hour, and separated. The organic layer was washed with water (500 mL), dried, concentrated, and recrystallized from ether to obtain tert-Butyl (2-(2,2-dimethyl-4H-benzo[d][1,3]dioxin-6-yl)-2-oxoethyl)carbamate 15.15g, yield 43 %.

tert-Butyl (2-(2,2-dimethyl-4H-benzo[d][1,3]dioxin-6-yl)-2-oxoethyl)carbamate

4248-19-5 Synthesis

4248-19-5
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$5.00/5g

102293-80-1 Synthesis

2-Bromo-1-(2,2-dimethyl-4H-benzo[d][1,3]dioxin-6-yl)ethanone

102293-80-1
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$265.00/250mg

452339-71-8
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Yield:452339-71-8 83%

Reaction Conditions:

Stage #1: tert-butyl carbazatewith lithium dipropan-2-ylazanide in tetrahydrofuran at -5 - 20; for 0.5 h;
Stage #2: 2-bromo-1-(2,2-dimethyl-4H-1,3-benzodioxin-6-yl)ethanone in tetrahydrofuran; for 2 h;Temperature;Reagent/catalyst;

Steps:

1-4 Example 1:

Add tert-butyl carbamate (225g, 1.1eq) to a 5L three-necked flask at room temperature,Add 500 mL of tetrahydrofuran and stir to dissolve, and bring the system to -5-0 °C,LDA (960mL, 2mol/L, 1.1eq) solution was slowly added dropwise,After adding, keep stirring for 0.5h.Then slowly add the solution prepared by 6-bromoacetyl-2,2-dimethyl-4H-benzo[1,3]dioxin (500g, 1.0eq) and 1L tetrahydrofuran into the reaction system dropwise,After the addition, the reaction was incubated for 2h. The middle control reaction is completed, the reaction solution is concentrated,Then saturated sodium bicarbonate solution (2L) and ethyl acetate (2L) were added,Stir to disperse the residue, separate the layers, and separate the organic layers with water (2L).washed with saturated brine (2L), then dried over anhydrous sodium sulfate,The magnesium sulfate was removed by filtration, and the solvent was removed by vacuum concentration.Add isopropyl ether (1L), stir at room temperature for crystallization,Filtration to obtain 467g of white powdery solid,Yield 83%, purity 99.1%.

References:

CN114736186,2022,A Location in patent:Paragraph 0012; 0018-0025

452339-70-7 Synthesis