9.3 g of aniline
Sulfuric acid (d = 1,84) 10 ml
7.3 g of sodium nitrite
60 ml ether
Porcelain cup of 250 ml
Round-bottomed flask of 500 ml
Dropping funnel
Agitator
Installation for steam distillation
Distillery phenol with a short air condenser
In a thick-walled glass pour 50 ml of water while stirring gently pour 190 ml of concentrated sulfuric acid was added 9.3 g of freshly distilled aniline. The solution was cooled to 0 0, gradually adding to it 75 g of finely divided ice with vigorous stirring to partially catching aniline sulfate was finely crystalline.
To the cooled mixture from the dropping funnel slowly, dropwise, with vigorous stirring, pour cooled to 0 - 50 solution of 7.3 g of sodium nitrite in 30 ml of water. The reaction temperature is not to exceed 8 0. When most of the sodium nitrite solution is already in the reaction mixture to stop pouring, and after 5 minutes take a sample for the presence of free nitric acid. To do this, a drop of solution is applied to iodkrahmalnuyu paper. If the paper does not appear blue spot, then you need to continue adding a solution of sodium nitrite. Simultaneously we should ensure that the solution always has an acid reaction (to Congo). Along with the presence of free nitric acid in the solution indicates the end of the reaction is complete transfer of aniline sulfate in solution.
Diazonium salt solution is transferred to a 500 ml flask and heated in a water bath (bath temperature of 50-60 0) until the evolution of nitrogen (15-20 min). The resulting phenol is distilled with steam as long as the sample distillate no longer give a turbidity bromine water. The distillate was saturated with sodium chloride and phenol extracted several times with ether (3 x 20 ml). Ether extracts were dried with anhydrous sodium sulfate or magnesium. Ether was removed, and phenol is distilled from a small flask, collecting the fraction 179-183 0. After cooling, the phenol must crystallize.
Yield of phenol was about 6 Phenol is in contact with skin burns. Therefore, when working with it, be careful. [3]
[3]. Albitskaya VG, Ginsburg OF, Kolyaskina ZN, Kupin BS, LA Pavlova, Razumova NA, Rall KB, Serkova VI Stadnichuk M. D. Laboratory work in organic chemistry. Ed. OF Ginzburg, AA Petrov. Vysshaya. wk., 1967. - With. 109-110.
Topic 2 – Technology for obtaining inorganic drugs (6 hours)
Objective: To master the technology for receiving and manufacturing of inorganic drugs.
Learning objectives:
1. Apply some of the techniques for the synthesis in the laboratory.
2. Practice basis physical methods for processing drugs (filtration, crystallisation, distillation, redistillation, preparation of saturated solutions, etc.).
3. Разрешить написание латиницей
The main issue in this topic:
1. Common methods of work in chemical synthesis.
2. Admission calculate the theoretical yield of the drug, if possible, the expected yield on the conditions of synthesis of drugs.
3. Analysis methods for the synthesis of barium sulfate.
Methods of learning and teaching: analysis of theoretical issues and practical tasks on the synthesis of inorganic medicinal substances.
References:
1 Альбицкая В.Г., Гинзбург О.Ф., Коляскина З.Н., Купин Б.С., Павлова Л.А., Разумова Н.А., Ралль К.Б., Серкова В.И., Стадничук М.Д. Лабораторные работы по органической химии. Под ред. О.Ф. Гинзбурга, А.А. Петрова. М.: Высш. шк., 1967. – 295 с.
2 Майофис Л.С. Химия и технология химико-фармацевтических препаратов. 2-е изд., перераб. и доп. – М.: Медицина, 1964. – 625 с.
