Hydrochloric Acid → 4-n-Propylamino-cyclohexanone-ethyleneketal

HRID 252205Notes

Reaction equation

HRID 252205 reaction equation
[CH2:1]([NH2:4])[CH2:2][CH3:3].Cl.[CH2:6]1[O:16][C:9]2([CH2:14][CH2:13][CH2:12][CH2:11][C:10]2=O)[O:8][CH2:7]1.C([BH3-])#N.[Na+].C(=O)([O-])[O-].[Na+].[Na+]>CO.O>[CH2:6]1[O:16][C:9]2([CH2:14][CH2:13][CH:12]([NH:4][CH2:1][CH2:2][CH3:3])[CH2:11][CH2:10]2)[O:8][CH2:7]1

Participants

8

Reactant 5

HCID 313Hydrochloric Acid2×HCID 7852PropylamineHCID 10340Sodium CarbonateHCID 5003444Sodium cyanoborohydrideHCID 123480741,4-Dioxaspiro[4.5]decan-6-one

Product 1

HCID 118200814-n-Propylamino-cyclohexanone-ethyleneketal

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Conditions

Temperature
2.5 °C

Procedure

A mixture of n-propyl amine (162 ml, 1.474 mol) in methanol (500 ml) was chilled to 0-5° C. To this solution was added methanolic hydrochloric acid (155 ml, 44.47%) dropwise over a period of 30 minutes to achieve a pH of 6-7. Cyclohexandione monoethyleneketal 1 (100 g, 0.641 mol) was charged at 5° C. and the reaction was stirred for 15 minutes. Sodium cyanoborohydride (60 g, 0.952 mol) was added in 15 minutes at 5° C. The pH increased to about 8 and methanolic hydrochloric acid (15 ml, 44.47%) was added to bring the pH to 6-7. The reaction was allowed to come to 24-26° C. Stirring was continued for 2 hours. Methanol was distilled off (450 ml). Sodium carbonate (95 g, 0.896 mol) was dissolved in water (850 ml) and charged to the reaction mass at ambient temperature in one shot. The reaction mass was extracted with dichloromethane (2500 ml). The dichloromethane layers were combined and dried over sodium sulfate (8.5 g). The dichloromethane layer was concentrated to dryness at 40° C. and 15 mbar pressure. The product 2 was light yellow viscous oil. The weight of the product 2 obtained was 135 g (105.8%); GC purity 97.74%.

Workup

  1. additionwas added
  2. customto come to 24-26° C
  3. stirringStirring
  4. waitwas continued for 2 hours
  5. distillationMethanol was distilled off (450 ml)
  6. additioncharged to the reaction mass at ambient temperature in one shot
  7. extractionThe reaction mass was extracted with dichloromethane (2500 ml)
  8. dry with materialdried over sodium sulfate (8.5 g)
  9. concentrationThe dichloromethane layer was concentrated to dryness at 40° C.

Sources & evidence

ORD record
ord-d6d730c398b54de084db5a508bfd1760
Source dataset
uspto-grants-2011_01
Patent number
US07868029B2

Reaction notes

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