Reaktion #358814

Reaktionsgleichung

1,2-dihydropyrane

p-toluene sulfonic acid

4-bromo-2 hydroxymethyl-5-methylthiophene

→

2-[(4-bromo-5-methylthiophen-2-yl)methoxy]tetrahydro-2H-pyrane

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISTILLATIONMethanol was distilled under vacuum
2. 2
   workup.DISTILLATIONthe remainder was distilled by an oil pump
3. 3
   SonstigeThe yield was 6.82 g of the product 10 (90%), Tmelt=125-130° C. (5 mm Hg), nd165=1.5610

Vorschrift

2.6 ml of 1,2-dihydropyrane and 0.2 g of p-toluene sulfonic acid were added to 5.4 g of 4-bromo-2 hydroxymethyl-5-methylthiophene 9 in 40 ml of methanol. The reaction mixture was stirred at room temperature for 24 hours. Methanol was distilled under vacuum and the remainder was distilled by an oil pump. The yield was 6.82 g of the product 10 (90%), Tmelt=125-130° C. (5 mm Hg), nd165=1.5610. Mass-spectrum, m/z: 291, [M]+. 1H NMR spectrum (CDCl3, δ, ppm, J/Hz): 1.45-1.95 (m, 6H, 3×CH2), 2.37 (s, 3H, CH3), 3.50-3.65 (m, 1H, CH), 3.80-4.0 (m, 1 H), 4.55-4.85 (m, 3H), 6.82 (s, 1 H, CH). The results found (%): C, 45.43; H, 5.20; S, 10.92. C11H15BrO2S. The results calculated (%): C, 45.37; H, 5.19; S, 11.01.

Quelle