Monday, August 26, 2019

1. Begin Experiment #2: Testing a synthesis of 2,2-dimethoxypropane from acetone and methanol with an H2SO4 catalyst. 

  1. In a conical 500 mL boiling flask were combined 20.12 grams of acetone (0.346 moles) with 33.30 grams (1.039 moles) of methanol. 5 grams of 98% H2SO4 were added to the flask and a reflux column (a 400mm Liebig capped with a glass stopper) was quickly attached to the flask. Stirring was turned on at 11:39. 
  2. The mixture was allowed to stir until it had cooled down a bit and then low heat was turned on. The mixture took on a very slightly yellow tint within the first 10 minutes of beginning the stirring. 
  3. By 12:19 the yellow tint of the solution had become stronger to the point that it could clearly be seen even at a distance of several meters. 
  4. By 12:45 the yellow color of the solution had become pronounced and the yellow had taken on a slightly orange tint. The solution was gently refluxing with a drop falling back into the solution once every 2 to 3 seconds. The heat was turned up slightly until one drop fell back into the solution about every 1 second. 
  5. By 13:10 the solution had gone completely orange in color. 
  6. By 14:03 the solution was a darkening orange that had the slightest hints of red. 
  7. At 14:18 the reflux column was repositioned as a distillation column and the contents of the flask were distilled at medium heat. The first liquid came over at 54 - 56 oC and finished at about 66 oC. 
  8. The distillate was fractionally distilled to see if the different boiling fractions could be further separated. However, the boiling profile did not change. FAIL.
    1. Further reading (Patent US4775447A) revealed that low temperatures favor the formation of 2,2-dimethoxypropane. Solvents must be dried more thoroughly.

Sunday, August 25, 2019

1. Continued Experiment #1 begun on Thursday, August 21, 2019. 

  1. The filtrate was poured into an evaporating dish which was put atop a beaker of water. The beaker was put on a hot plate which was turned on high. The water in the beaker boiled and the steam slowly evaporated the filtrate down while keeping the temperature below 100 oC in order to minimize any thermal decomposition of the product. 
  2. The filtrate evaporated off over the course of several hours yielding a slightly orange tinted yellow solid.
  3. The melting point was measured as 202 - 204 oC. Anthranilic acid has a melting point of 146 - 148 oC. 

Thursday, August 21, 2019

1. Synthesized elemental bromine as described in the grimoire under Synthesis of Elemental Bromine

2. Prepared a fresh batch of anhydrous magnesium sulfate for drying of solvents. 

3. Begin Experiment #1: Testing reduction of 2-nitrobenzoic acid (hereafter 2-NBA) by tin metal in HCl(aq)

  1. Combine 0.49 grams of 2-NBA with 50 mL of 0.1M HCl. The 2-NBA would not dissolve even with vigorous stirring (as expected)
  2. 20 drops of concentrated HCl were added to the beaker while stirring was continued. No change in the solubility occurred (again, as expected)
  3. 4.52 grams of thin tin pieces that were cut into small chunks with wire cutters were added to the flask with vigorous stirring at room temperature. 
  4. After about 10 minutes the solution began to look visibly different. It took on a yellow color and the tin turned black. The amount of solid suspended in the solution was visibly decreasing over the course of about 10 to 15 minutes.
  5. After about 20 minutes the solution began to take on a very slight but noticeable blueish tinge. The amount of suspended solid 2-NBA is almost negligible at this point.
  6. After about 25 minutes the solution took on a somewhat gray color due to the presence of tiny black particles suspended by the vigorous stirring. Solid particles of 2-NBA are not present by this point. 
  7. Within 40 minutes all of the yellow coloration and blueish tints had disappeared and the solution appears to be more or less clear except for the grayish tinge imparted to it from the tiny particles of a black 
  8. After about an hour and 15 minutes stirring was stopped and the suspension of tiny black particles was allowed to settle out so that the true color of the solution could be clearly seen. It was observed that the solution was clear and colorless and no particles of 2-NBA were seen. 
  9. The solution was filtered through a piece of cotton to remove the black particulates and remaining tin metal. The cotton plug and metal fragments were rinsed twice using a squirt bottle of distilled water. 
  10. A small H2S generator was set up using 6M H2SO4 and chips of Na2S. The gas was bubbled through the filtrate obtained in the previous step in four large bursts.
  11. The H2S precipitated dark brown solid tin(II) sulfide immediately. The fourth burst of the gas caused an unknown dark mirror to form on the sides of the flask. 
  12. The dark brown solid was filtered out of the solution through a cotton plug. The filtrate was covered and set aside to be worked on in the future. 

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