Methyl acetoacetate → Isoprene

HRID 46464

Reaction equation

HRID 46464 reaction equation
CC([O-])C.CC([O-])C.CC([O-])C.[Al+3].[CH3:14][C:15](=[CH:17][CH2:18][CH2:19][C:20](=[O:22])[CH3:21])[CH3:16].[CH3:23][C:24]([OH:28])([CH:26]=[CH2:27])[CH3:25].C(OC)(=O)CC(C)=O>>[CH3:14][C:15](=[CH:17][CH2:18][CH2:19][C:20](=[O:22])[CH3:21])[CH3:16].[CH3:23][C:24]([OH:28])([CH:26]=[CH2:27])[CH3:25].[CH2:18]=[CH:17][C:15](=[CH2:14])[CH3:16]

Participants

7

Reactant 4

HCID 7757Methyl acetoacetateHCID 82572-Methyl-3-buten-2-ol2×HCID 98626-Methyl-5-hepten-2-oneHCID 11143Aluminum isopropoxide

Product 3

HCID 6557IsopreneHCID 82572-Methyl-3-buten-2-olHCID 98626-Methyl-5-hepten-2-one

Conditions

Temperature
150 °C

Procedure

7.5 g of aluminum triisopropylate and 50 g of a reaction product which contains 42 g of 2-methyl-2-hepten-6-one and 5 g of 2-methyl-3-buten-2-ol are heated at 150° C. in the reaction apparatus described in Example 1, and a mixture of 464 g of methyl acetoacetate and 430 g of 2-methyl-3-buten-2-ol is introduced in the course of 18 hours. On working up the mixture by distillation when the reaction has ceased, 490 g of 2-methyl-2-hepten-6-one, 95 g of unconverted 2-methyl-3-buten-2-ol, 13 g of acetone and 4 g of isoprene are obtained. The yield (448 g) is 89% of theory, based on methyl acetoacetate employed, and 90.1%, based on methylbutenol converted.

Workup

  1. additionis introduced in the course of 18 hours
  2. distillationby distillation when the reaction

Sources & evidence

ORD record
ord-63235544baeb4a01bcd04c12e75ec3ce
Source dataset
uspto-grants-1979_11
Patent number
US04173588

Linked notes

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