Lithium Hydroxide → Thieno[2,3-d]thiophene-2,6-dicarboxylic acid
Reaction equation
C(C1SC2[C:11]3[S:14][C:15]4[C:19](CCCCCCCCCCCCCCCCC)=[C:18]([C:37]([O:39]CC)=[O:38])[S:17][C:16]=4[C:10]=3SC=2C=1CCCCCCCCCCCCCCCCC)(OCC)=O.[Li+].[OH-:60].C1[CH2:65][O:64]CC1>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.CO>[S:17]1[C:16]2[C:10]([C:65]([OH:64])=[O:60])=[CH:11][S:14][C:15]=2[CH:19]=[C:18]1[C:37]([OH:39])=[O:38]Participants
Procedure
Ester deprotection (Step C) The 2,6-dicarboethoxy-3,7-diheptadecylthieno[3,2-b]thieno[2′,3′:4,5]thieno[2,3-d]thiophene (26.0 g, 30 mmol) product of Example 2, LiOH (2.9 g, 121 mmol in 29 mL water), THF (100 mL), MeOH (20 mL) and a catalytic amount (about 35 mg) of tetrabutylammonium bromide were combined in a round bottomed flask fitted with a condenser and heated at reflux overnight. Approximately 90% of the solvent was evaporated and the residue was acidified to pH 1 with concentrated hydrochloric acid to form a solid which was collected by filtration, washed thoroughly with water and methanol, and dried under vacuum to yield 3,7-diheptadecanyl thieno[3,2-b]thieno[2′:3′:4,5]thieno[2,3-d]thiophene-2,6-dicarboxylic acid (23.5 g, 96% yield). 1H NMR (D8-THF) δ 0.88 (6H, m), 1.20-1.50 (72H, m), 1.70-1.87 (4H, m), and 3.23 (4H, m).
Workup
- customfitted with a condenser
- temperatureheated
- temperatureat reflux overnight
- customApproximately 90% of the solvent was evaporated
- customto form a solid which
- filtrationwas collected by filtration
- washwashed thoroughly with water and methanol
- customdried under vacuum
Sources & evidence
- ORD record
- ord-7711f1487234484899e9ab47871bc3ba
- Source dataset
- uspto-grants-2012_07
- Patent number
- US08217183B2
Reaction notes
Loading…