Methyl iodide → Lithium cyclohexylisopropylamide

HRID 329325

Reaction equation

HRID 329325 reaction equation
[CH2:1]([Li:5])CCC.[CH:6]([NH:9][CH:10]1[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1)([CH3:8])[CH3:7].[O:16]=[C:17]1[C:23]2[CH:24]=[CH:25][C:26]([CH2:28][C:29]([O:31][CH2:32][CH3:33])=[O:30])=[CH:27][C:22]=2[CH:21]=[CH:20][C:19]2[CH:34]=[CH:35][CH:36]=[CH:37][C:18]1=2.CI>CCOCC.O.O1CCCC1>[CH:6]([N-:9][CH:10]1[CH2:15][CH2:14][CH2:13][CH2:12][CH2:11]1)([CH3:8])[CH3:7].[Li+:5].[O:16]=[C:17]1[C:23]2[CH:24]=[CH:25][C:26]([CH:28]([CH3:1])[C:29]([O:31][CH2:32][CH3:33])=[O:30])=[CH:27][C:22]=2[CH:21]=[CH:20][C:19]2[CH:34]=[CH:35][CH:36]=[CH:37][C:18]1=2

Participants

9

Reactant 4

HCID 6328Methyl iodideHCID 62386CyclohexylisopropylamineHCID 53675848ethyl (5-oxo-5H-dibenzo[a,d]cyclohepten-2yl)acetateHCID 178418339Butyllithium

Product 2

HCID 10877271Lithium cyclohexylisopropylamideHCID 20310707ethyl 2-(5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)propionate

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-80 °C

Procedure

Lithium isopropylcyclohexylamide is prepared by adding 10 mls. of 1.0 molar n-butyl lithium to a solution of 1.41 g. of isopropylcyclohexylamine in 100 ml. of dry tetrahydrofuran. To this solution, cooled to -80° C, there is added a solution of 2.94 g. of ethyl (5-oxo-5H-dibenzo[a,d]cyclohepten-2yl)acetate (as prepared in Example I above) in 10 ml. of tetrahydrofuran. The mixture is left for 5 minutes, then 1.42 g. of methyl iodide is added. The reaction mixture is allowed attain room temperature, then water and ether are added. The ethereal layer is washed with dilute hydrochloric acid and water, dried and evaporated to yield ethyl 2-(5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)propionate. This ethyl ester is refluxed for 12 hrs. in 5% aqueous potassium hydroxide, followed by acidification with dilute hydrochloric acid and ether extraction to afford dl 2-(5-oxo-5H-dibenzo[a,d]cyclohepten-2-yl)propionic acid (m.p. 138°-139° C, 113°-115° C). This mixture of optical isomers can exist in two crystalline forms. The form having the higher melting point is obtained by using chloroform/hexane as the recrystallizing solvent, while the form having the lower melting point is obtained by using acetone/hexane as the recrystallizing solvent.

Workup

  1. additionby adding 10 mls
  2. additionthere is added a solution of 2.94 g
  3. customis allowed attain room temperature
  4. washThe ethereal layer is washed with dilute hydrochloric acid and water
  5. customdried
  6. customevaporated

Sources & evidence

ORD record
ord-eda6494917924075841371dfb50c0550
Source dataset
uspto-grants-1977_04
Patent number
US04020094

Linked notes

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