Reaktion #46512

Reaktionsgleichung

HCl

SnCl4

2-methylbenzo[b]thiophene

dichloromethyl methyl ether

→

title compound

Ausbeute 98.2%

2-Methylbenzo[b]thiophene-3-carboxaldehyde

Ausbeute 98.2%

Lösungsmittel

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas poured onto ice water (200 mL)
2. 2
   workup.STIRRINGstirred until the suspension
3. 3
   workup.DISSOLUTIONdissolved
4. 4
   SonstigeThe organic phase was separated
5. 5
   Trocknendried (MgSO4)
6. 6
   Einengenconcentrated under vacuum
7. 7
   SonstigePurification by flash chromatography on silica gel (10% ethyl acetate/hexane)

Vorschrift

SnCl4 (20 mL, 67 mmole) was added over 5 min to a stirred solution of 2-methylbenzo[b]thiophene (5.0 g, 33.7 mmole) in CH2Cl2 (75 mL) at 0° C. under argon. After 15 minutes, dichloromethyl methyl ether (3.7 mL, 41 mmole) was added. The reaction became a yellowish colored suspension. The reaction was allowed to warm to RT and stirred for 16 h, then was poured onto ice water (200 mL). The aqueous mixture was acidified with 1.0 N HCl (100 mL) and stirred until the suspension dissolved. The organic phase was separated, dried (MgSO4), and concentrated under vacuum. Purification by flash chromatography on silica gel (10% ethyl acetate/hexane) gave the title compound (5.83 g, 98%) as a white crystalline solid: 1H NMR (400 MHz, CDCl3) δ 10.38 (s, 1 H), 8.61 (d, J=8.1 Hz, 1 H), 7.77 (d, J=8.0 Hz, 1 H), 7.48 (t, 1 H), 7.39 (t, 1 H), 2.93 (s, 3 H).

Quelle