ChemicalBook CAS DataBase List 3-METHYLTHIOPHENE-2-BORONIC ACID PINACOL ESTER

3-METHYLTHIOPHENE-2-BORONIC ACID PINACOL ESTER synthesis

5synthesis methods

Product Name:3-METHYLTHIOPHENE-2-BORONIC ACID PINACOL ESTER
CAS Number:885692-91-1
Molecular formula:C11H17BO2S
Molecular Weight:224.13

61676-62-8 Synthesis

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

61676-62-8
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$10.00/5g

3-METHYLTHIOPHENE-2-BORONIC ACID PINACOL ESTER

885692-91-1
124 suppliers
$75.00/100mg

Yield: 53%

Reaction Conditions:

Stage #1:2-bromo-3-methylthiophene with n-butyllithium in tetrahydrofuran;hexane at -40; for 0.5 h;
Stage #2:2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane in tetrahydrofuran;hexane at 20; for 1 h;

Steps:

4.b
To a stirred solution of 2-bromo-3-methythiophene (337 mg, 1.9 mmol) in 8 mL of THF at -40 ^°C was added n-BuLi (0.8 mL, 2.5 M/hexanes), and the reaction was allowed to stir for 30 min. At this time 2-isopropoxy-4,4,5,5-tetramethyl-[l,3,2]dioxaborolane (775 μL, 3.8 mmol) was added, and the reaction was allowed to warm to ambient temperature, and stirring was continued for 1 h. The reaction was then cooled to 0 C and quenched with satd aq NaHCO₃ (10 mL). The mixture was poured into EtOAc (100 mL), washed with H₂O (2 x 50 mL), dried (Na₂SO₄) and concentrated in vacuo. Purification of the residue by silica gel preparative thin layer chromatography (20 % EtOAc-hexanes) afforded 224 mg (53 %) of the title compound as an oil. ¹H- NMR (CDCl₃; 400 MHz): δ 1.36 (s, 12H), 2.5 (s, 3H), 6.99 (d, IH, J = 4.8 Hz), 7.50 (d, IH, J = 4.8 Hz).

References:

JANSSEN PHARMACEUTICA, N.V. WO2006/47277, 2006, A2 Location in patent:Page/Page column 44

14282-76-9 Synthesis