Phosphoric Acid → Cyclopentanone, 2-(1-hydroxypentyl)-

Participants

Reaction Conditions

Reaction Steps

Valeraldehyde having an acid value of 1.0 mg-KOH/g was used as the starting material. 112.3 g (1.34 mol) cyclopentanone, 50.0 g water and 0.24 g (0.0029 mol) 48% NaOH were introduced into a 500-mL four-necked flask, then the mixture was cooled to 15° C. under stirring, and 50.0 g (0.58 mol) valeraldehyde was added dropwise at the same temperature over 5 hours. Thereafter, the mixture was stirred at the same temperature for 2 hours. After the reaction was finished, the mixture was neutralized with 0.23 g (0.0025 mol) 105% condensed phosphoric acid and separated into two layers at 40° C. The resulting organic layer was 170.4 g, and the aqueous layer was 42.4 g. The pH of the aqueous layer was 5.5. The organic layer was analyzed in the same manner as in Example 1. The result indicated that the reaction mixture contained 86.0 g (0.505 mol) 2-(1-hydroxy-n-pentyl)cyclopentanone (yield 87.2%), 2.29 g (0.015 mol) 2-pentylidene cyclopentanone and 1.9 g (0.011 mol; content 1.1%) cyclopentanone dimer, and the aqueous layer contained 2.8 g cyclopentanone. 58.3 g cyclopentanone and 8 g water could be recovered by distillation from the organic layer. The phosphoric acid contained in the aqueous layer, as determined by titration with NaOH for converting it into trisodium phosphate, was 0.0062 mol.

Provenance & Evidence