Ethyl Acetate → 2-(2-Ethyl-4-formylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonane

HRID 276306Notes

Reaction equation

HRID 276306 reaction equation
[C:1]([C:3]1[CH:8]=[CH:7][C:6]([N:9]=[C:10]2[S:14][CH2:13][C:12]3([CH2:18][CH2:17][CH2:16][CH2:15]3)[N:11]2[CH:19]2[CH2:23][CH2:22][CH2:21][CH2:20]2)=[C:5]([CH2:24][CH3:25])[CH:4]=1)#N.CC(C[AlH]CC(C)C)C.CC[O:37]C(C)=O>C1(C)C=CC=CC=1>[CH2:24]([C:5]1[CH:4]=[C:3]([CH:1]=[O:37])[CH:8]=[CH:7][C:6]=1[N:9]=[C:10]1[S:14][CH2:13][C:12]2([CH2:18][CH2:17][CH2:16][CH2:15]2)[N:11]1[CH:19]1[CH2:23][CH2:22][CH2:21][CH2:20]1)[CH3:25]

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 14487Diisobutylaluminum hydrideHCID 98199572-(4-Cyano-2-ethylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonane

Product 1

HCID 183160482-(2-Ethyl-4-formylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonaneYield 75%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
-78 °C

Procedure

2-(4-Cyano-2-ethylphenylimino)-3-thia-1-azaspiro[4.4]nonane was prepared in a manner analogous to Method C2a and the thiazolidine was alkylated in a manner analogous to Method D2b to give 2-(4-cyano-2-ethylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonane. To a solution of 2-(4-cyano-2-ethylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonane (0.21 g, 0.60 mmol) in anh. toluene (20 mL) at −78C. was added DIBAL (1.0M in toluene, 1.20 mL, 1.20 mmol). The reaction mixture was stirred at −78° C. for 3 h, then EtOAc (3 mL) was added at −78° C., stirring was continued for 0.5 h, and wet silica gel (5% water, 2 g) was added. The reaction mixture was warmed to room temp., stirred for 3 h, then filtered through a pad of through Celite®. The filtrate was concentrated under reduced pressure, and the residue was purified by preparative TLC (30% EtOAc/hex) to give 2-(2-ethyl-4-formylphenylimino)-1-cyclopentyl-3-thia-1-azaspiro[4.4]nonane as a white solid (0.16 g, 75%): mp 104-105° C.

Workup

  1. stirringstirring
  2. waitwas continued for 0.5 h
  3. additionwet silica gel (5% water, 2 g) was added
  4. temperatureThe reaction mixture was warmed to room temp.
  5. stirringstirred for 3 h
  6. filtrationfiltered through a pad of through Celite®
  7. concentrationThe filtrate was concentrated under reduced pressure
  8. customthe residue was purified by preparative TLC (30% EtOAc/hex)

Sources & evidence

ORD record
ord-4655d755bf9845f4a91d711ab87effcb
Source dataset
uspto-grants-2002_03
Patent number
US06353006B1

Reaction notes

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