Hydrochloric Acid → Dimethylamine, hydrochloride

HRID 1021070Notes

Reaction equation

HRID 1021070 reaction equation
[CH3:1][NH:2][CH3:3].[ClH:4].[CH2:5]=O.[CH2:7]1[CH2:17][C:15](=[O:16])[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[CH2:8]1>O>[ClH:4].[CH3:1][NH:2][CH3:3].[ClH:4].[CH3:1][N:2]([CH2:5][CH:17]1[CH2:7][CH2:8][C:9]2[C:14](=[CH:13][CH:12]=[CH:11][CH:10]=2)[C:15]1=[O:16])[CH3:3]

Participants

7

Reactant 4

HCID 313Hydrochloric Acid3×HCID 674Dimethylamine2×HCID 712Formaldehyde3×HCID 107241-Tetralone2×

Product 2

HCID 10473Dimethylamine, hydrochlorideHCID 1998671(2H)-Naphthalenone, 2-((dimethylamino)methyl)-3,4-dihydro-, hydrochloride (1:1)

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

First, 6.83 g of a 50% by mass aqueous dimethylamine solution (dimethylamine: 75.9 mmol) was added to a 100-ml two-necked flask. Next, 8.19 g of a 35% by mass aqueous solution of hydrochloric acid (hydrochloric acid: 78.9 mmol) was added to a 100-ml dropping funnel. Subsequently, the dropping funnel was set to the two-necked flask, and then the aqueous solution of hydrochloric acid was added dropwise to the aqueous dimethylamine solution under ice-cooling. Thus, dimethylamine hydrochloride was prepared in the two-necked flask. Next, 2.78 g (92.4 mmol) of paraformaldehyde as the formaldehyde derivative and 9.0 g (61.6 mmol) of α-tetralone as the carbonyl compound were further added to the two-necked flask. Note that the volume of the mixture made of water and paraformaldehyde present in the two-necked flask was 25 mL, and the concentration of hydrochloric acid (HCl) in the mixture was 0.12 mol/L. Subsequently, a bulb condenser was set to the two-necked flask, and then the inside of the two-necked flask was replaced with nitrogen. Thereafter, the two-necked flask was immersed in an oil bath of 90° C., and heated for 4 hours with stirring. Thus, a reaction liquid was obtained. Note that the thus obtained reaction liquid was subjected to HPLC analysis for components in the reaction liquid. As a result, the conversion of α-tetralone was found to be 99%, and the yield (HPLC yield) of N,N-dimethylaminomethyl-1-tetralone hydrochloride (the Mannich base) was found to be 95%.

Workup

  1. temperaturecooling
  2. customSubsequently, a bulb condenser was set to the two-necked flask
  3. customThereafter, the two-necked flask was immersed in an oil bath of 90° C.
  4. temperatureheated for 4 hours
  5. customThus, a reaction liquid
  6. customwas obtained
  7. customNote that the thus obtained reaction liquid
  8. customwas subjected to HPLC analysis for components in the reaction liquid

Sources & evidence

ORD record
ord-1ceb1fb2da40471db98470c0a8bd45c3
Source dataset
uspto-grants-2014_05
Patent number
US08716531B2

Reaction notes

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