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Dapivirine Synthesis Essay

A Guide to Synthesizing Sources


  1. What is a synthesis? 
    A synthesis is a written discussion incorporating support from several sources of similar or differing views. This type of assignment requires that you examine a variety of sources and identify their relationship to your thesis.
  2. Synthesis is used in:
    • Analysis papers to examine related theories.
      • Ex.: a comparison between the theories of evolution or who shot JFK.
    • Research/explanatory papers to incorporate multiple sources.
      • Ex.: a look at economic and social effects of proposed legislation.
    • Argument papers to compare differing views and support a coherent claim.
      • Ex.: Are plagiarism checkers a violation of student’s rights? One side may argue that these companies steal students’ papers while others claim that students agree to have their work archived.
    • Business reports to examine differing ideas and blend into a coherent plan.
      • Ex.: What are some of the plans to improve Toledo’s waterfront to attract more visitors and increase business opportunities?
  3. Tips for effective synthesis:
    • Establish your purpose to shape the way you want to argue and form your thesis. The thesis is the main claim or idea of your essay.
    • Select your sources and become familiar with them so that you can discuss them in relationship to your thesis and supporting argument(s). If you simply quote sources without evaluating them, then the sources will control your paper and your audience may misinterpret the information.
    • Develop an organizational plan. Arrange more than just one source per point; multiple sources will increase your credibility. Look at how sources may agree or disagree with one another, and evaluate which source has better logic or more credibility.
    • Evaluate or interpret each source, then show the relationship between the sources and your thesis.
    • Document each source according to established citation guidelines in the style specified by your instructor (MLA, APA, etc.). This MUST be done if you quote, summarize, or paraphrase a source.
  4. Strategies for organization:
    • Climactic order arranges the most important/persuasive evidence last since this is what is remembered.
    • Problem/solution establishes the problem in the introduction, and then offers a few solutions.
    • Comparison and contrast
      • Summarizes each source and shows their similarities and differences.
      • Can move from point-to-point, back and forth between items being compared.
  5. Analyze the position of each source; you can use these verbs to note the author’s tone:
  6. Argumentative:

    • affirms
    • argues
    • confirms
    • contends
    • denies
    • disagrees
    • believes
    • concedes
    • insists
    • rejects
    • responds
    • emphasizes

    Explanatory:

    • adds
    • reveals
    • states
    • mentions
    • finds
    • verifies

    Emphatic:

    • alleges
    • warns
    • advises
    • admits
    • complains
    • holds
    • predicts
    • proposes
    • acknowledges
    • speculates
    • suggests
  7. Which tense do I use?
    • MLA- use present tense: Shakespeare writes...
    • APA- use past tense: Dr. Bombay affirmed the value...
  8. If you have any questions, contact your instructor, refer to your course textbook, and visit the Writing Center.

2.1.2. Synthesis of Red Dye DR1

3-(N,N-Diethyl)amino-acetylaniline (11.00 g, 0.053 mol) was dissolved in ethanol (40 mL) at 20 °C and to this solution concentrated hydrochloric acid (20 mL) was added dropwise. The mixture was heated up to 70 °C and reacted for 10 h. The 3-(N,N-diethyl)amino-aniline (1) was obtained.

p-Nitroaniline (0.690 g, 5.0 mmol), 10 mL of water, and 3 mL of concentrated hydrochloric acid were stirred for 0.5 h at 75 °C. Then, the mixture was cooled to 0–5 °C and sodium nitrite (0.38 g, 5.5 mmol) was quickly added to obtain the corresponding p-nitroaniline diazonium salt solution. The course of the reaction was confirmed by thin-layer chromatography (petroleum ether:ethyl acetate, 4:1; Rf = 0.25). Raw material was fully converted after 20 min.

Cyanuric chloride (3.68 g, 0.02 mol), toluene (10 mL), and 3-(N,N-diethyl)amino-aniline (1) (3.28 g, 0.02 mol) were mixed at 5 °C and stirred for 1 h. After that, the reaction solution was filtrated to give a gray filter cake of product 2.

Intermediate 2 (1.550 g, 5 mmol) was dissolved in acetic acid (15 mL) and water (50 mL) at 5 °C. Concentrated hydrochloric acid (2 mL) was added to the above solution and then p-nitroaniline diazonium salt solution was added dropwise. The course of the reaction was confirmed by thin-layer chromatography (toluene:acetone, 6:1, Rf = 0.95). The solid 3 was obtained via neutralization to pH 7 with sodium hydroxide solution.

Product 3 (0.461 g, 1 mmol) and 0.18 mL of 3-aminopropyldimethylmethoxylsilane were then dissolved in tetrahydrofuran (60 mL). Then, the solution was warmed to 30 °C and stirred for 0.5 h. The course of the reaction was confirmed by thin-layer chromatography (toluene:acetone, 6:1; Rf = 0.75). The red solid was collected by filtration and dried to obtain 0.362 g of red dye DR1 (yield 63%).

DR1 purification was done by column chromatography (dichloromethane:ethyl acetate, 10:1; v/v).

The synthesis of red dye DR2 (yield 61%) and DR3 (yield 63%) was similar to the method used in the preparation of DR1 (3-aminopropylmethyldimethoxylsilane and 3-aminopropyltrimethoxylsilane instead of 3-aminopropylmethoxyldimethylsilane were used, respectively).

2.1.3. Synthesis of Purple Dye DP1

3-(N,N-Diethyl)amino-acetylaniline (11.00 g, 0.053 mol) was dissolved in ethanol (40 mL) at 20 °C. To this solution, concentrated hydrochloric acid (20 mL) was added dropwise, the mixture was heated up to 70 °C, and the reaction was continued for 10 h. 3-(N,N-Diethyl)amino-aniline (1) was obtained.

Sulfuric acid 98% (5 g, 0.05 mol) was added into sodium nitrite (0.38 g, 5.5 mmol) at room temperature, and stirred for 10 min. The mixture was cooled to 0–5 °C and 6-bromo-2,4-dinitro-aniline (1.31 g, 5.0 mmol) was added. The course of the reaction was confirmed by thin-layer chromatography (petroleum ether:ethyl acetate, 4:1; Rf = 0.25). Raw material was fully converted after 1 h. 6-Bromo-2,4-dinitro-aniline diazonium salt solution was obtained.

Cyanuric chloride (3.68 g, 0.02 mol), toluene (10 mL), and 3-(N,N-diethyl)amino-aniline (1) (3.28 g, 0.02 mol) were mixed at 5 °C and reacted for 1 h. After that, the reaction solution was filtrated to give gray filter cake of product 2.

Intermediate 2 (1.550 g, 5 mmol) was dissolved in acetic acid (15 mL) and water (50 mL) at 5 °C. Concentrated hydrochloric acid (2 mL) was added to the above solution and then p-nitroaniline diazonium salt solution was added dropwise. The course of the reaction was confirmed by thin-layer chromatography (toluene:acetone, 6:1; Rf = 0.95). The solid 3 was obtained via neutralization to pH 7 with sodium hydroxide solution.

Product 3 (0.585 g, 1 mmol) and 0.18 mL of 3-aminopropylmethoxyldimethylsilane were dissolved in tetrahydrofuran (60 mL). Then, the solution was warmed to 30 °C and stirred for 0.5 h. The course of the reaction was confirmed by thin-layer chromatography (toluene:acetone, 6:1; Rf = 0.75). The purple solid was collected by filtration and dried to obtain 0.411 g of purple dye DP1 (yield 59%).

DP1 purification was done by column chromatography (dichloromethane:ethyl acetate, 10:1; v/v).

The synthesis of red dye DP2 (yield 58%) and DP3 (yield 57%) was similar to the method used in the preparation of DP1 (3-aminopropylmethyldimethoxylsilane and 3-aminopropyltrimethoxylsilane instead of 3-aminopropylmethoxyldimethylsilane were used, respectively).

2.1.5. Structure Characterization Results of Reactive Disperse Silicon-Containing Dyes (Please see in Supplementary Materials)

Red dye DR1: C25H34ClN9O3Si: MS (API-ES) [M + H]+: 572. 1H-NMR data (ppm): (CDCl3, 400 MHz) δ: 0.07 (s, 6H), 0.56 (t, J = 6.6 Hz, 2H), 1.26 (t, J = 6.4 Hz, 6H), 1.85–1.86 (m, 2H), 3.01–3.02 (m, 2H), 3.49–3.50 (m, 4H), 3.44–3.45 (m, 3H), 5.32–5.33 (m, 2H), 6.39–6.41 (m, 1H), 7.75–7.86 (m, 3H), 8.16–8.29 (m, 3H). FT-IR (KBr, cm−1): 3407, 3273 (N-H); 1587, 1564, 1473 (benzene ring or cyanide ring); 1520, 1327 (NO2); 1261 (Si-Me); 1178, 1101, 1078 (Si-OMe). UV-Vis (nm): 512.1; molar absorptivity (L·mol−1·cm−1): 2.40 × 104.

Red dye DR2: C25H34ClN9O4Si: MS (API-ES) [M + H]+: 588. 1H-NMR data (ppm): (CDCl3, 400 MHz) δ: 0.15 (s, 3H), 0.70 (t, J = 8.0 Hz, 2H), 1.30 (t, J = 6.8 Hz, 6H), 1.85–1.86 (m, 2H), 3.50–3.54 (m, 12H), 6.48–6.49 (m, 1H), 7.76–7.89 (m, 3H), 8.15–8.31 (m, 3H). FT-IR (KBr, cm−1): 3398, 3356, 3265 (N-H); 1562, 1473 (benzene ring or cyanide ring); 1516, 1325 (NO2); 1259 (Si-Me); 1176, 1101, 1076 (Si-OMe). UV-Vis (nm): 511.9; molar absorptivity (L·mol−1·cm−1): 2.41 × 104.

Red dye DR3: C25H34ClN9O5Si: MS (API-ES) [M + H]+: 604. 1H-NMR data (ppm): (CDCl3, 400 MHz) δ: 0.72 (t, J = 8.0 Hz, 2H), 1.30 (t, J = 6.8 Hz, 6H), 1.77–1.78 (m, 2H), 3.51–3.60 (m, 15H), 6.44–6.46 (m, 1H), 7.76–7.87 (m, 3H), 8.15–8.29 (m, 3H). FT-IR (KBr, cm−1): 3396, 3373, 3267 (N-H); 1585, 1562, 1475 (benzene ring or cyanide ring); 1518, 1327 (NO2); 1178, 1101, 1078 (Si-OMe); 1176, 1101, 1076 (Si-OMe). UV-Vis (nm): 512.0; molar absorptivity (L·mol−1·cm−1): 2.40 × 104.

Purple dye DP1: C25H32BrClN10O5Si: MS (API-ES) [M + H]+: 697. 1H-NMR data (ppm): (CDCl3, 600 MHz) δ: 0.14 (s, 6H), 0.68 (t, J = 6.6 Hz, 2H), 1.35 (t, J = 6.4 Hz, 6H), 1.68–1.70 (m, 2H), 3.47 (s, 3H), 3.47–3.48 (m, 2H), 3.57–3.60 (m, 4H), 6.51–6.53 (m, 2H), 6.99–6.70 (m, 1H), 8.39–8.39 (m, 1H), 8.66–8.66 (m, 1H). FT-IR (KBr, cm−1): 3417, 3361, 3269 (N-H); 1579, 1566, 1473 (benzene ring or cyanide ring); 1527, 1319 (NO2); 1259 (Si-Me); 1196, 1072 (Si-OMe). UV-Vis (nm): 553.5; molar absorptivity (L·mol−1·cm−1): 1.66 × 104.

Purple dye DP2: C25H32BrClN10O6Si: MS (API-ES) [M + H]+: 713. 1H-NMR data (ppm): (DMSO-d6, 400 MHz) δ: 0.11 (s, 3H), 0.66 (t, J = 8.0 Hz, 2H), 1.30 (t, J = 6.8 Hz, 6H), 1.62–1.74 (m, 2H), 3.22 (s, 6H), 3.46–3.49 (m, 2H), 3.50–3.67 (m, 4H), 6.83–6.85 (m, 1H), 7.59–7.60 (m, 1H), 8.21–8.22 (m, 1H), 8.54 (s, 1H), 8.74–8.75 (m, 1H). FT-IR (KBr, cm−1): 3417, 3361, 3269 (N-H); 1566, 1473 (benzene ring or cyanide ring); 1527, 1319 (NO2); 1259 (Si-Me); 1196, 1072 (Si-OMe). UV-Vis (nm): 553.4; molar absorptivity (L·mol−1·cm−1): 1.66 × 104.

Purple dye DP3: C25H32BrClN10O7Si: MS (API-ES) [M + H]+: 729. 1H-NMR data (ppm): (DMSO-d6, 400 MHz) δ: 0.48 (t, J = 8.0 Hz, 2H), 1.28 (t, J = 6.8 Hz, 6H), 1.65–1.67 (m, 2H), 3.22 (s, 9H), 3.50–3.63 (m, 6H), 6.77–6.79 (m, 1H), 7.52–7.53 (m, 1H), 8.16–8.18 (m, 1H), 8.48–8.50 (m, 1H), 8.72 (d, J = 7.2 Hz, 1H,). FT-IR (KBr, cm−1): 3407, 3363, 3269 (N-H); 1564, 1473 (benzene ring or cyanide ring); 1527, 1321 (NO2); 1196, 1074 (Si-OMe). UV-Vis (nm): 553.1; molar absorptivity (L·mol−1·cm−1): 1.66 × 104.