SYNTHESIS OF ASPIRIN SYNTHESIS PURIFICATION CHARACTERIZATION

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1 SYNTHESIS F ASPIRIN SYNTHESIS PURIFICATIN CHARACTERIZATIN

2 ASPIRIN: SME BACKGRUND PATENTED BY BAYER IN 1893 NE F THE LDEST DRUGS NE F THE MST CNSUMED DRUGS (PRDUCTIN IN THE US IS 10 MILLIN KG/YEAR)

3 ASPIRIN: BILGICAL ACTIVITY ANALGESIC (PAINKILLER) ANTIPYRETIC (FEVER REDUCER) ANTI-INFLAMMATRY (INHIBITIN F THE SYNTHESIS F PRSTAGLANDINS) SIDE EFFECTS: GASTRIC IRRITATIN, BLEEDING APPARITIN F NEW ANALGESICS (TYLENL)

4 ASPIRIN: THE MLECULE H acetyl salicylic acid (aspirin)

5 RGANIC BACKGRUND ALCHLS ALCHLS R H ALIPHATIC ALCHLS: HYDRXYL DERIVATIVES F SATURATED HYDRCARBNS H 3 C H methanol ethanol ENLS: HYDRXYL DERIVATIVES F UNSATURATED HYDRCARBNS R H H H R enol phenol

6 RGANIC BACKGRUND CARBXYLIC ACIDS R H H H H. C H H formic acid acetic acid benzoic acid

7 RGANIC BACKGRUND ESTERIFICATIN R 1 H + H + H R 2 R 1 R 2 carboxylic acid alcool ester This is an equilibrium!

8 RGANIC BACKGRUND ESTERIFICATIN MECHANISM H + H H 2 + R 1 H H R 2 R 1 H R 1 H carboxylic acid alcool R 2 + H R 2 -H + R 1 ester R 2

9 RGANIC BACKGRUND ACIDITY: A REVIEW BRNSTED-LWRY ACID SUBSTANCE THAT CAN DNATE A PRTN LEWIS ACID SUBSTANCE THAT ACCEPTS LNE-PAIR ELECTRNS AH + H 2 A - + H 3 + K A = [H 3 + ][A - ] / [AH] PK A = -LG K A Acid pk a water 14.0 Acetic acid 4.75 Benzoic acid 4.19 Formic acid 3.75 Sulfuric acid 1

10 REACTIN H H H 2 S 4 + heat + H H acetic anhydride salicylic acid acetyl salicylic acid (aspirin) acetic acid

11 REACTIN MECHANISM H H + H + H H H -H + H + H

12 SYNTHESIS PRCEDURE MIX SALICYLIC ACID (SLID) WITH ACETIC ANHYDRIDE (LIQUID) AND A CATALYTIC AMUNT F H 2 S 4. HEAT FR 10 MIN AT 90 0 C. CL DWN T RM TEMPERATURE AND ADD WATER (CRYSTALLIZATIN SLVENT). INDUCE CRYSTALLIZATIN. FILTER THE CRYSTALS.

13 PURIFICATIN BY RECRYSTALLIZATIN WHAT IS RECRYSTALLIZATIN? METHD RAPID AND CNVENIENT WAY F PURIFYING A SLID RGANIC CMPUND THE MATERIAL T BE PURIFIED IS DISSLVED IN THE HT APPRPRIATE SLVENT AS THE SLVENT CLS, THE SLUTIN BECME SATURATED WITH RESPECT T THE SUBSTANCE, WHICH THEN CRYSTALLIZE IMPURITIES STAY IN SLUTIN CHSE THE SLVENT DISSLVE THE SLUTE (FILTER SUSPENDED SLIDS) CRYSTALLIZE THE SLUTE CLLECT AND WASH THE CRYSTALS DRY THE CRYSTALS

14 ASSESSMENT F PURITY: LKING FR PRPERTIES PHYSICAL PRPERTIES CHEMICAL PRPERTIES PHYSICAL APPEARANCE SLUBILITY MELTING PINT INFRARED SPECTRA PERCENT YIELD PTENTIMETRIC TITRATIN PHENL TEST

15 ASSESSMENT F PURITY: PHYSICAL APPEARANCE PHYSICAL STATE (SLID? LIQUID?..) CLR DR TEXTURE HMGENEITY IN CMPSITIN

16 ASSESSMENT F PURITY: SLUBILITY (NN MANDATRY) IN A TEST TUBE, TRANSFER A SMALL AMUNT F YUR PRDUCT (END F A SPATULA) ADD ~1/2ML F SLVENT DETERMINE SLUBILITY AT RM TEMPERATURE IF NT, GENTLY HEAT AND DETERMINE SLUBILITY AT HIGHER TEMPERATURE TEST SEVERAL RGANIC SLVENTS AND CMPARE WITH LITTERATURE

17 ASSESSMENT F PURITY: MELTING PINT MELTING PINT CHARACTERIZE THE CMPUND RANGE F THE MELTING PINT INDICATE THE PURITY F THE CMPUND METHD: SCANNING F THE TEMPERATURE UNTIL MELTING CCURS. DETERMINE START AND END TEMPERATURE F MELTING. DN T HEAT T FAST!! (<1 0 C / MIN)

18 ASSESSMENT F PURITY: INFRARED SPECTRA DISSLVE THE PRDUCT IN CHLRFRM AND BTAIN THE IR SPECTRUM. YU CAN ALS PREPARE A PELLET IN KBR. ASSIGN THE PEAKS D YU SEE IMPURITIES? CMPARE WITH THE REFERENCE SPECTRUM.

19 ASSESSMENT F PURITY: PERCENT YIELD DEFINITIN: %YIELD = N EXP /N TH WRITE DWN THE REACTIN WITH THE CRRECT STECHIMETRY. EX: A+B C PREPARE A CHART LIKE BELW AND CALCULATE YIELD. m A (g) or V A (ml) n A (mol) m B (g) or V B (ml) n B (mol) m C (g) theoretical n C (mol) theoretical m c (g) experimental n C (mol) experimental

20 ASSESSMENT F PURITY: PHENL TEST AND VISIBLE SPECTRSCPY PHENL REACT WITH FECL 3 (AQ) T GIVE A DEEP PURPLE CMPLEX. PHENL IS NT PRESENT IN THE PRDUCT BUT IN NE F THE REACTANT. THIS TEST INDICATE THE PRESENCE F UNREACTED STARTING MATERIAL (QUANTITATIVE ANALYSIS PSSIBLE VIA VISIBLE SPECTRSCPY).

21 H H + Fe 3+ Deep purple complex salicylic acid

22 ACETYLSALICYLIC ACID (MRE CMMNLY KNWN AS ASPIRIN) BY VIKTR PLITES

23 CHEMICAL STRUCTURE FRMULA: C 9 H 8 4 SYSTEMATIC NAME: 2-ACETXYBENZIC ACID HAS A BENZENE RING BACKBNE CARBXYLIC ACID ESTER GRUP N THE 2ND CARBN IN BENZENE RING.

24 PHYSICAL PRPERTIES Density: 1.40 g/cm 3 Melting Point: 135 C Boiling Point: 140 C Solubility in Water: 3 mg/ml at 20 C

25 CHEMICAL PRPERTIES ACETYLSALICYLIC ACID SLWLY DECMPSES BY HYDRLYSIS INT ACETIC AND SALICYLIC ACIDS IN THE AQUEUS MEDIUM. HYDRLYSIS F ACETYLSALICYLIC ACID IS ACCELERATED IN SLUTINS F AMMNIUM ACETATE, R ACETATATES, CARBNATES, CITRATES, R HYDRXIDES F THE ALKALI METALS. ACETYLSALICYLIC ACID IS A WEAK ACID WITH AN ACID DISSCIATIN CNSTANT, KA, F 3.2 X 10^-4.

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