Tổng Hợp Aspirin (Axit Axetylsalixylic)

Chế tạo một trong những loại thuốc phổ biến nhất thế giới

Organic Synthesis Advanced (University) 90 phút ~$15,00

Mục tiêu

Tổng hợp aspirin (axit axetylsalixylic) bằng axetyl hóa axit salixylic với anhydrit axetic, và đánh giá độ tinh khiết bằng xác định điểm nóng chảy.

Bối cảnh

Aspirin synthesis is a classic organic chemistry experiment. Salicylic acid reacts with acetic anhydride in the presence of a phosphoric acid catalyst to form acetylsalicylic acid and acetic acid. The product is purified by recrystallization and verified by melting point (135°C for pure aspirin).

Cảnh báo an toàn

  • Acetic anhydride is corrosive and has a pungent odor — work in fume hood
  • Phosphoric acid is corrosive
  • Do not consume the synthesized aspirin
  • Wear gloves and goggles

PPE cần thiết

goggles gloves lab_coat

Vật liệu

  • Salicylic acid (2 g)
  • Acetic anhydride (5 mL)
    Corrosive, pungent
  • Phosphoric acid (H₃PO₄) (5 drops)
    85%, catalyst
  • Distilled water (100 mL)
    Ice-cold for crystallization
  • Ethanol (10 mL)
    For recrystallization

Thiết bị

Erlenmeyer flask (125 mL) Hot water bath (beaker) Buchner funnel Filter flask Vacuum pump Melting point apparatus Thermometer Ice bath

Quy trình

1

Weigh 2.0 g of salicylic acid into the Erlenmeyer flask. Record the exact mass.

3 phút
2

In a fume hood, add 5 mL of acetic anhydride and 5 drops of phosphoric acid catalyst.

3 phút Acetic anhydride is corrosive and pungent
3

Heat the flask in a water bath at 70-80°C for 15 minutes, swirling occasionally.

15 phút
4

Remove from heat and carefully add 20 mL of cold water to decompose excess acetic anhydride.

3 phút Exothermic — add water slowly
5

Cool the flask in an ice bath until crystals form. Scratch the flask wall with a glass rod to initiate crystallization.

10 phút
6

Collect the crude product by vacuum filtration using the Buchner funnel. Wash with cold water.

10 phút
7

Recrystallize: dissolve the crude product in 5 mL warm ethanol, add 15 mL warm water, then cool slowly in ice bath.

15 phút
8

Collect purified crystals by vacuum filtration. Dry and determine the melting point.

10 phút
9

Calculate the percent yield. Pure aspirin melts at 135°C.

5 phút

Kết quả dự kiến

White needle-like crystals with a melting point of 134-136°C (pure aspirin is 135°C). Typical yield is 70-90%. A depressed or broad melting range indicates impurities (likely unreacted salicylic acid).

Dọn dẹp

Dispose of organic waste in designated containers. Do not consume the product. Rinse all glassware.

Chi tiết

Danh mục
Organic Synthesis
Độ khó
Advanced (University)
Thời gian
90 phút
Chi phí ước tính
$15,00
Số bước
9
Vật liệu
5

Thí nghiệm khác

Chế Tạo Nylon 6,10 (Thủ Thuật Sợi Nylon) 30 min Chiết Xuất Caffeine Từ Trà 90 min Điều Chế Axetaminophen (Paracetamol) 80 min Este Hóa Fischer Để Tổng Hợp Etyl Axetat 90 min Làm Xà Phòng Bằng Xà Phòng Hóa 60 min Ngưng Tụ Aldol (Dibenzalaxeton) 75 min Sản Xuất Biodiesel Từ Dầu Thực Vật 60 min Tổng Hợp Dầu Chuối (Isoamyl Axetat) 90 min Tổng Hợp Luminol 120 min Tổng Hợp Slime (PVA Khâu Mạch) 20 min

Frequently Asked Questions

What is the objective of Tổng Hợp Aspirin (Axit Axetylsalixylic)?
Tổng hợp aspirin (axit axetylsalixylic) bằng axetyl hóa axit salixylic với anhydrit axetic, và đánh giá độ tinh khiết bằng xác định điểm nóng chảy.
How difficult is Tổng Hợp Aspirin (Axit Axetylsalixylic)?
This experiment is rated as Advanced (University). It takes approximately 90 minutes to complete.
What safety precautions are needed for Tổng Hợp Aspirin (Axit Axetylsalixylic)?
Key safety precautions include: Acetic anhydride is corrosive and has a pungent odor — work in fume hood; Phosphoric acid is corrosive; Do not consume the synthesized aspirin.
What materials are needed for Tổng Hợp Aspirin (Axit Axetylsalixylic)?
The main materials required are: Salicylic acid, Acetic anhydride, Phosphoric acid (H₃PO₄), Distilled water, Ethanol.
What results should I expect from Tổng Hợp Aspirin (Axit Axetylsalixylic)?
White needle-like crystals with a melting point of 134-136°C (pure aspirin is 135°C). Typical yield is 70-90%. A depressed or broad melting range indicates impurities (likely unreacted salicylic acid).