ChemicalBook CAS DataBase List 4,4,5,5-tetramethyl-2-(thieno[3,2-b]thiophen-2-yl)-1,3,2-dioxaborolane

4,4,5,5-tetramethyl-2-(thieno[3,2-b]thiophen-2-yl)-1,3,2-dioxaborolane synthesis

6synthesis methods

Product Name:4,4,5,5-tetramethyl-2-(thieno[3,2-b]thiophen-2-yl)-1,3,2-dioxaborolane
CAS Number:1004784-50-2
Molecular formula:C12H15BO2S2
Molecular Weight:266.19

251-41-2 Synthesis

251-41-2
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61676-62-8 Synthesis

2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

61676-62-8
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4,4,5,5-tetramethyl-2-(thieno[3,2-b]thiophen-2-yl)-1,3,2-dioxaborolane

1004784-50-2
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Yield:1004784-50-2 85.4%

Reaction Conditions:

Stage #1: thieno[3,2-b]thiophenewith n-butyllithium in tetrahydrofuran;hexane at -70; for 1 h;Inert atmosphere;
Stage #2: 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane in tetrahydrofuran;hexane at -70 - 20; for 16 h;Inert atmosphere;

Steps:

41.1 Step 1: 4,4,5,5-tetramethyl-2-(thieno[3,2-b]thiophen-2-yl)-1,3,2-dioxaborolane (149)

[0602] To a solution of 148 (5 g, 35.65 mmol) in THF (70 mL) was added n-BuLi (1.6 M in hexanes, 23.4 mL, 37.4 mmol) at -70 °C dropwise for 30 min with stirring under N2 atmosphere. After addition, the reaction was stirred at the same temperature for 30 min, followed by the addition of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (7.29 g, 39.2 mmol). The reaction was allowed to warm to room temperature and stirred for 16 hrs. After quenched with saturated aq. NH4Cl solution at 0 ^oC, the mixture was extracted with EtOAc twice. The combined organic layers are washed with brine, dried over anhydrous Na₂SO₄ and concentrated to dryness to give the title compound (8.1 g, 85.4% yield) as light green solid.

References:

WO2017/35357,2017,A1 Location in patent:Paragraph 0416; 0602

251-41-2 Synthesis

251-41-2
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$8.00/250mg

76-09-5 Synthesis