Citric Acid → HCID 57508884, compound
Reaction equation
[CH3:1][C:2]1([CH3:14])[CH2:13][CH2:12][C:5]2=[C:6]([C:9]([OH:11])=[O:10])[S:7][CH:8]=[C:4]2[CH2:3]1.[C:15]([Li])(C)(C)C.CI.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>C1COCC1.O>[CH3:15][C:8]1[S:7][C:6]([C:9]([OH:11])=[O:10])=[C:5]2[CH2:12][CH2:13][C:2]([CH3:14])([CH3:1])[CH2:3][C:4]=12Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Procedure
At −78° C. a solution of 5,5-dimethyl-4,5,6,7-tetrahydro-benzo[c]thiophene-1-carboxylic acid (5 g, 23.8 mmol) in THF is treated with tert.-butyllithium (41 mL, 1.5 M in pentane). The mixture is stirred at −78° C. for 15 min before methyliodide (17.1 g, 120 mmol) is added dropwise. Stirring is continued at −78° C. for 30 min. The mixture is warmed to rt, diluted with water (400 mL), acidified with 10% aq. citric acid solution and extracted three times with EA. The combined organic extracts are dried over MgSO4 and evaporated. The remaining solid is suspended in heptane/diethyl ether, filtered and dried under HV to give 3,5,5-trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophene-1-carboxylic acid (4.01 g) as a beige powder; LC-MS: tR=0.97 min, [M+1]=225.13; 1H NMR (D6-DMSO): δ 12.49 (s br, 1H), 2.87 (t, J=6.7 Hz, 2H), 2.26 (s, 5H), 1.45 (t, J=6.7 Hz, 2H), 0.91 (s, 6H).
Workup
- additionis added dropwise
- extractionextracted three times with EA
- dry with materialThe combined organic extracts are dried over MgSO4
- customevaporated
- filtrationfiltered
- customdried under HV
Sources & evidence
- ORD record
- ord-d4acafdb8ac94d60953781cbad0ac0f9
- Source dataset
- uspto-grants-2010_05
- Patent number
- US07723378B2
Reaction notes
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