Reaktion #1601027

Reaktionsgleichung

methanol

Lithium hydroxide

2,6,-dicarboethoxy-3,7-diheneicosylthieno[3,2-b]thieno[2′,3′:4,5]thieno[2,3-d]thiophene

product

2,6-dicarboethoxy-3,7-diheneicosylthieno[3,2-b]thieno[2′,3′:4,5]thieno[2,3-d]thiophene

methanol

→

3,7-diheneicosyl thieno[3,2-b]thieno[2′,3′:4,5]thieno[2,3-d]thiophene-2,6-dicarboxylic acid

Lösungsmittel

water

tetrahydrofuran

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA condenser is fitted
2. 2
   SonstigeThe THF and methanol are removed under reduced pressure
3. 3
   workup.ADDITION60 ml, of methanol and 10 mL of conc. hydrochloric acid are added
4. 4
   workup.ADDITIONNext 50 mL of water is added
5. 5
   Filtrationthe solid is filtered off
6. 6
   SonstigeThe product is dried under vacuum

Vorschrift

Ester deprotection (Step C) The 2,6,-dicarboethoxy-3,7-diheneicosylthieno[3,2-b]thieno[2′,3′:4,5]thieno[2,3-d]thiophene (10 mmol) product of Example 10, is dissolved in tetrahydrofuran (THF) (280 mL) then methanol (40 mL) is added. Lithium hydroxide (40 mmol) is dissolved in water (10 mL) and added to the stirred methanol and THF solution. A condenser is fitted and the reaction mixture is heated in an oil bath at 90° C. for 16 hr. The THF and methanol are removed under reduced pressure. 60 ml, of methanol and 10 mL of conc. hydrochloric acid are added then stirred for 4 h. Next 50 mL of water is added and the solid is filtered off. The product is dried under vacuum to give the 3,7-diheneicosyl thieno[3,2-b]thieno[2′,3′:4,5]thieno[2,3-d]thiophene-2,6-dicarboxylic acid. 1H NMR (D8-THF) δ 0.89 (6H, t, J=6.9 Hz), 1.17-1.45 (72H, m), 1.68-1.85 (4H, m), and 3.18-3.28 (4H, m).

Quelle