Diethyl Ether → 1-(3,5,5-Trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanone

HRID 1013440Notes

Reaction equation

HRID 1013440 reaction equation
[CH3:1][C:2]1[S:6][C:5]([C:7]([OH:9])=O)=[C:4]2[CH2:10][CH2:11][C:12]([CH3:15])([CH3:14])[CH2:13][C:3]=12.[CH2:16](OCC)C>C[Li]>[CH3:1][C:2]1[S:6][C:5]([C:7](=[O:9])[CH3:16])=[C:4]2[CH2:10][CH2:11][C:12]([CH3:15])([CH3:14])[CH2:13][C:3]=12

Participants

4

Reactant 2

HCID 3283Diethyl EtherHCID 57508884HCID 57508884, compound

Product 1

HCID 574374241-(3,5,5-Trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanone

Reagents, catalysts & solvents 1

HCID 178418348HCID 178418348, compoundSolvent

Conditions

Temperature
26 °C

Procedure

To a suspension of 3,5,5-trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophene-1-carboxylic acid (4.10 g, 18.28 mmol) in diethyl ether (300 mL), methyllithium (23 mL, 1.6 M solution in diethyl ether) is slowly added at rt. The reaction mixture becomes clear, yellow and slightly warm (26° C.), and is stirred for 15 min before it is quenched with water. The organic layer is separated, washed once more with water, dried over MgSO4 and evaporated. The crude product is purified by CC on silica gel eluting with heptane:EA 4:1 to give 1-(3,5,5-trimethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanone (2.80 g) as a pale yellow crystalline solid; LC-MS: tR=1.06 min; [M+1]=223.17; 1H NMR (CDCl3): δ 3.00 (t, J=7.0 Hz, 2H), 2.43 (s, 3H), 2.31 (s, 3H), 2.26 (s, 2H), 1.51 (t, J=7.0 Hz, 2H), 0.95 (s, 6H).

Workup

  1. additionis slowly added at rt
  2. customis quenched with water
  3. customThe organic layer is separated
  4. washwashed once more with water
  5. dry with materialdried over MgSO4
  6. customevaporated
  7. customThe crude product is purified by CC on silica gel eluting with heptane:EA 4:1

Sources & evidence

ORD record
ord-b8246a2fb5594e6d8b362b56020867e2
Source dataset
uspto-grants-2011_07
Patent number
US07981924B2

Reaction notes

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