Sulfuric Acid → 3-(4-Pyridinyl)-2-cyclohexen-1-one oxime

HRID 1389914Notes

Reaction equation

HRID 1389914 reaction equation
C(=O)CCCC(=[O:7])C.[N:9]1C=CC(C2CCCC(=O)C=2)=[CH:11][CH:10]=1.C1(=O)CCCC=C1.O=C(C)CC[CH:33]([C:39]([C:41]1[CH:46]=[CH:45][N:44]=CC=1)=O)[C:34](OCC)=O.S(=O)(=O)(O)O.[CH:53](O)([CH3:55])[CH3:54]>>[N:9]1[CH:10]=[CH:11][C:55]([C:41]2[CH2:39][CH2:33][CH2:34][C:45](=[N:44][OH:7])[CH:46]=2)=[CH:53][CH:54]=1

Participants

7

Reactant 6

HCID 1118Sulfuric AcidHCID 3776IsopropanolHCID 135942-Cyclohexen-1-oneHCID 9835014Ethyl 2-(isonicotinoyl)-5-oxohexanoateHCID 109534665-OxohexanalHCID 134025703-(4-Pyridinyl)-2-cyclohexen-1-one

Product 1

HCID 30174583-(4-Pyridinyl)-2-cyclohexen-1-one oxime

Procedure

This invention resides in an improvement in the process for preparing 3-(4-pyridinyl)-2-cyclohexen-1-oxime by heating ethyl 5-oxo-2-[(4-pyridinyl)carbonyl]hexanoate under aqueous acidic conditions to produce 1-(4-pyridinyl)-hexan-1,5-dione, reacting said hexan-1,5-dione with a basic condensing agent to produce said 3-(4-pyridinyl)-2-cyclohexen-1-one, and converting said cyclohexen-1-one to its oxime, said improvement being a one pot sequence consisting of first heating ethyl 5-oxo-2-[(4-pyridinyl)carbonyl]hexanoate with excess aqueous sulfuric acid, neutralizing the excess acid, shaking the resulting mixture well with isopropyl alcohol to extract the 3-(4-pyridinyl)-2-cyclohexen-1-one, draining off the heavier warm (40° to 50° C.) aqueous layer, adding hydroxylamine hydrochloride to the isopropyl alcohol solution of 3-(4-pyridinyl)-2-cyclohexen-1-one, stirring the mixture at reflux, basifying the mixture and evaporating it to dryness, and isolating the 3-(4-pyridinyl)-2-cyclohexen-1-one oxime from the residue. In a preferred embodiment three mole-equivalents of sulfuric acid were used per mole of ethyl 5-oxo-2-[(4-pyridinyl)carbonyl]hexanoate, the excess sulfuric acid was neutralized with aqueous sodium hydroxide solution and the reaction mixture was basified after oxime formation with concentrated ammonium hydroxide.

Workup

  1. customto produce
  2. extractionto extract the 3-(4-pyridinyl)-2-cyclohexen-1-one
  3. temperatureheavier warm (40° to 50° C.) aqueous layer
  4. additionadding hydroxylamine hydrochloride to the isopropyl alcohol solution of 3-(4-pyridinyl)-2-cyclohexen-1-one
  5. temperatureat reflux
  6. customevaporating it to dryness

Sources & evidence

ORD record
ord-6f97fe72949e49158a1674c4f67416d6
Source dataset
uspto-grants-1981_01
Patent number
US04246420

Reaction notes

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