Amphetamine Sulphate Overacidification Correcting Method

[GhostChemist]

Introduction​

The topic represents a correcting errors method in a case of accidental addition of excessive amount of sulfuric acid during acidifiacation procedure. Over-acidification less than 5.5 pH cause the dissolution of the target amphetamine sulphate precipitate and spoilage of the product.​

General scheme of the processes. Scheme 1

Scheme 1​

Starting reagents and materials​

• 3 g AMP sulfate
• 50-100 ml IPA
• 20 ml IPA + H2SO4 (concentration unknown)
• 30-60 g NaOH
• 200-250 ml H2O
• Beakers
• Separating funnel 250 ml
• Pipettes
• pH-indicator strips
• Filters

Procedures​

The process of amphetamine sulfate dissolution in H2SO4/IPA solution. Scheme 2

Scheme 2​

Amphetamine sulphate is placed into a beaker Fig 1

Fig 1​

Amphetamine solution of ~25% sodium hydroxide is prepared (30 g in 100-120 ml H2O) Fig 2

Fig 2​

20-25 ml of IPA is added to the amphetamine sulfate. Fig 3

Fig 3​

Sulfuric acid solution in IPA is added dropwise until amphetamine sulfate is dissolved (Scheme 2) Fig 4

Fig 4​

The formation of the amphetamine free base occurs according to Scheme 3

Scheme 3​

An alkali solution is added to the amphetamine hydrosulfate solution. Fig 5

Fig 5​

25-50 ml of IPA is added to the resulting mixture. Fig 6

Fig 6​

The mixture is transferred to a separatory funnel and the upper layer of IPA containing free base amphetamine is separated. If the separation is poor, an additional portion of alkali (25-30% solution) and IPA is added. Fig 7

Fig 7​

The formation of amphetamine sulfate again is shown in Scheme 4.

Scheme 4​

A solution of sulfuric acid in IPA is slowly added to the IPA layer with constant stirring, drop by drop, until the mixture reaches a neutral reaction. Fig 8

Fig 8​

The mixture should have a neutral pH. Fig 9

Fig 9
​

The resulting precipitate was filtered off. Fig 10

Fig 10​

The precipitate is dried on the filter Fig 11

Fig 11​

Yield is 2.95-3 g Fig 12

Fig 12​

Confirmation of consist amphetamine - adding a granule of alkali to the sample and a drop of water - a specific smell of the amphetamine free base should appear.

The impurity is an inert and safe salt sodium sulfate.

To obtain the purer product, steam distillation of the free base is used.​

 

[ruen]

so.. you are making amphetamine sulfate from amphetamine sulfate? what am i missing here?

 

[GhostChemist]

stage of acidifying of fb