Reaction #2691

Reaction equation

t-Butyllitium

TMEDA

Bis-(2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']-bis(1,3)dithiole-4-yl)-mono-(2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']-bis(1,3)dioxol-4-yl)methanol

diethyl carbonate

→

Bis-(8-ethoxycarbonyl-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']-bis(1,3)dithiole-4-yl)-mono-(8-ethoxycarbonyl-2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']-bis(1,3)dioxol-4-yl)methanol

Solvents

benzene

benzene

Conditions

Workup

1. 1
   Otherultrasound for 25 min.
2. 2
   OtherThe organic layer was separated
3. 3
   Washwashed with water
4. 4
   Dryingdried (Na2SO4)
5. 5
   Otherevaporated
6. 6
   OtherAfter purification by preparative HPLC 130.0 mg (21%)) of the pure product
7. 7
   Otherwas obtained

Procedure

Bis-(2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']-bis(1,3)dithiole-4-yl)-mono-(2,2,6,6-tetramethylbenzo[1,2-d:4,5-d']-bis(1,3)dioxol-4-yl)methanol (0.50 g, 0.61 mmol) was dissolved in dry benzene (6.0 mL) under an atmosphere of argon. t-Butyllitium (2.44 mL, 1.5M in pentane) and TMEDA (0.545 mL, 3.66 mmol) were added. The reaction mixture was subjected to ultrasound for 25 min. and was then slowly added to a solution of diethyl carbonate (7.2 mL, 59.4 mmol) in dry benzene (16 mL). After stirring for 1.5 h, aqueous NaH2PO4 (50 mL) was added. The organic layer was separated, washed with water, dried (Na2SO4) and evaporated. After purification by preparative HPLC 130.0 mg (21%)) of the pure product was obtained. 1H NMR (CDCl3, 300 MHz) δ: 4.98 (s, 1H), 4.28-4.37 (m, 6H), 1.48-1.79 (m, 36H), 1.46 (t, 6H, J 7.0 Hz), 1.38 (t, 3H, J 7.0 Hz).

Source