ChemicalBook CAS DataBase List 2,5-bis(4,4,5,5-tetraMethyl-1,3,2-dioxaborolan-2-yl)thieno[3,2-b]thiophene

2,5-bis(4,4,5,5-tetraMethyl-1,3,2-dioxaborolan-2-yl)thieno[3,2-b]thiophene synthesis

5synthesis methods

Product Name:2,5-bis(4,4,5,5-tetraMethyl-1,3,2-dioxaborolan-2-yl)thieno[3,2-b]thiophene
CAS Number:924894-85-9
Molecular formula:C18H26B2O4S2
Molecular Weight:392.15

251-41-2 Synthesis

251-41-2
273 suppliers
$8.00/250mg

61676-62-8 Synthesis

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

61676-62-8
311 suppliers
$10.00/5g

2,5-bis(4,4,5,5-tetraMethyl-1,3,2-dioxaborolan-2-yl)thieno[3,2-b]thiophene

924894-85-9
50 suppliers
$53.00/100mg

Yield: 61.25%

Reaction Conditions:

Stage #1:thieno[3,2-b]thiophene with n-butyllithium in tetrahydrofuran;hexanes at -78; for 1.16667 h;Inert atmosphere;Cooling with ice;
Stage #2:2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane in tetrahydrofuran;hexanes
Stage #3: with ammonium chloride in tetrahydrofuran;hexanes;water

Steps:

To a solution of thieno[3,2-b]thiophene (1 .5 g, 10.70 mmol) in THF (25.5 mL) at -78 °C under N ₂ is added dropwise a solution of BuLi in hexanes (8.988 mL of 2.5 M, 22.47 mmol), stirred for 20 min, cooling bath is replaced with ice bath and stirred for 50 min. The resultant thick suspension is quenched with 2- isopropoxy-4,4,5,5-tetramethyl-1 ,3,2-dioxaborolane (4.181 g, 4.584 mL, 22.47 mmol). The reaction mixture is kept for overnight and then quenched with saturated aq. NH₄Cl solution. After extraction with CH₂Cl₂ (2 x 100 mL), the combined extracts are washed with brine and dried (Na₂S0₄). Organic solution is diluted with -20 mL of ethyl acetate, concentrated slowly on rotary evaporator until CH₂Cl₂ is removed. The resultant white fine crystals are collected by filtration. The solid is washed with heptanes and dried under high vacuum to afford 4,4,5,5-tetramethyl-2-[5-(4,4,5,5-tetramethyl-1 ,3,2- dioxaborolan-2-yl)thieno[3,2-b]thiophen-2-yl]-1 ,3,2-dioxaborolane (2.57 g, 6.554 mmol, 61.25%) as half-white solid. ¹H NMR (400 MHz, CDCl₃) δ 7.75 (s, 2H), 1.343 (s, 12H).

References:

VERTEX PHARMACEUTICALS INCORPORATED;DAS, Sanjoy Kumar;BENNANI, Youssef L. WO2011/119853, 2011, A1 Location in patent:Page/Page column 126-127

25121-87-3 Synthesis