thiocyanic acid

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the stirred solution of thiocyanic acid is added a solution of the crude dl-α-phenyl-1-aziridineethanol in 250 ml. of ethanol at a rate sufficient to keep the reaction temperature at 30°-35° C. After the aziridine addition is complete, 72 g. of a methanolic solution of hydrogen chloride (0.35 mole) is added and the solution stirred for 1.5 hours at room temperature. An additional 0.05 mole of hydrogen chloride in 10 g. of ethanol is added, and the reaction heated at 35°-40° C. for 0.5 hour. It is then allowed to proceed at room temperature for 2.5 days. The mixture is concentrated under reduced pressure to about 100 ml., filtered, washed with ethanol and dried to give 27.1 g. of white crystals, melting point 198°-200° C. The yield is 42% (based on styrene oxide) or 71% (based on dl-α-phenyl-1-aziridineethanol). at 30°-35° C the reaction heated at 35°-40° C. for 0.5 hour to proceed at room temperature for 2.5 days The mixture is concentrated under reduced pressure to about 100 ml , filtered washed with ethanol dried to give 27.1 g

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To the stirred solution of thiocyanic acid is added a solution of the crude dl-α-phenyl-1-aziridineethanol in 250 ml. of ethanol at a rate sufficient to keep the reaction temperature at 30°-35° C. After the aziridine addition is complete, 72 g. of a methanolic solution of hydrogen chloride (0.35 mole) is added and the solution stirred for 1.5 hours at room temperature. An additional 0.05 mole of hydrogen chloride in 10 g. of ethanol is added, and the reaction heated at 35°-40° C. for 0.5 hour. It is then allowed to proceed at room temperature for 2.5 days. The mixture is concentrated under reduced pressure to about 100 ml., filtered, washed with ethanol and dried to give 27.1 g. of white crystals, melting point 198°-200° C. The yield is 42% (based on styrene oxide) or 71% (based on dl-α-phenyl-1-aziridineethanol). at 30°-35° C the reaction heated at 35°-40° C. for 0.5 hour to proceed at room temperature for 2.5 days The mixture is concentrated under reduced pressure to about 100 ml , filtered washed with ethanol dried to give 27.1 g

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This process was allegedly further improved by stripping the loaded solvent with a saturated aqueous solution of ammonium sulfate containing some sulfuric acid, the extract phase containing thiocyanic acid, ammonium sulfate, and the hafnium values in the form of hafnium thiocyanate. Such extract phase is then treated with gaseous ammonia, which reacts with the thiocyanic acid and hafnium thiocyanate to simultaneously form ammonium thiocyanate and hafnium hydroxide. This is said to be of the utmost importance in coprecipitating ammonium sulfate with the hafnium hydroxide to make the hafnium hydroxide easily filterable, see the aforementioned Greenberg et al., U.S. Pat. No. 3,069,232 of Dec. 18, 1962 entitled "Recovery of Hafnium Values." However, not only is the sulfate ion present, but the sulfuric acid introduced into the ammonium sulfate extractant to ensure recovery of the major portion of the thiocyanic acid in the extract phase, contaminates the extract phase and requires additional purification steps. Such extract phase is then treated with gaseous ammonia, which reacts with the thiocyanic acid and hafnium thiocyanate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This process was allegedly further improved by stripping the loaded solvent with a saturated aqueous solution of ammonium sulfate containing some sulfuric acid, the extract phase containing thiocyanic acid, ammonium sulfate, and the hafnium values in the form of hafnium thiocyanate. Such extract phase is then treated with gaseous ammonia, which reacts with the thiocyanic acid and hafnium thiocyanate to simultaneously form ammonium thiocyanate and hafnium hydroxide. This is said to be of the utmost importance in coprecipitating ammonium sulfate with the hafnium hydroxide to make the hafnium hydroxide easily filterable, see the aforementioned Greenberg et al., U.S. Pat. No. 3,069,232 of Dec. 18, 1962 entitled "Recovery of Hafnium Values." However, not only is the sulfate ion present, but the sulfuric acid introduced into the ammonium sulfate extractant to ensure recovery of the major portion of the thiocyanic acid in the extract phase, contaminates the extract phase and requires additional purification steps. Such extract phase is then treated with gaseous ammonia, which reacts with the thiocyanic acid and hafnium thiocyanate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This process was allegedly further improved by stripping the loaded solvent with a saturated aqueous solution of ammonium sulfate containing some sulfuric acid, the extract phase containing thiocyanic acid, ammonium sulfate, and the hafnium values in the form of hafnium thiocyanate. Such extract phase is then treated with gaseous ammonia, which reacts with the thiocyanic acid and hafnium thiocyanate to simultaneously form ammonium thiocyanate and hafnium hydroxide. This is said to be of the utmost importance in coprecipitating ammonium sulfate with the hafnium hydroxide to make the hafnium hydroxide easily filterable, see the aforementioned Greenberg et al., U.S. Pat. No. 3,069,232 of Dec. 18, 1962 entitled "Recovery of Hafnium Values." However, not only is the sulfate ion present, but the sulfuric acid introduced into the ammonium sulfate extractant to ensure recovery of the major portion of the thiocyanic acid in the extract phase, contaminates the extract phase and requires additional purification steps. Such extract phase is then treated with gaseous ammonia, which reacts with the thiocyanic acid and hafnium thiocyanate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 12 g. of 2-mercapto-4,5-diphenyl-oxazole (m.p. 252°-254°, from methanol; obtainable from 4,5-diphenyl-2-oxazolone and phosphorus pentasulfide in boiling xylene, or by the reaction of benzoin with HSCN) is dissolved in 100 ml. of DMF, and 1.2 g. of NaH is added thereto. The reaction mixture is agitated for 1.5 hours at room temperature. Then, 5.6 ml. of the ethyl ester of bromoacetic acid in 20 ml. of DMF is added dropwise thereto, and the reaction mixture is stirred for 2 hours at 80° . The mixture is then mixed with water and worked up as usual, thus obtaining the ethyl ester of 4,5-diphenyl-2-oxazolyl-mercaptoacetic acid, b.p. 207°-210°/0.1mm.; m.p. 54°-56° (hexane). is dissolved in 100 ml the reaction mixture is stirred for 2 hours at 80°

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: reacting 5,7-difluoro-1,2,3,4-tetrahydronaphthalen-2-ylamine with thiocyanic acid and dihydroxyacetone to give 5-hydroxymethyl-1-(5,7-difluoro-1,2,3,4-tetrahydronaphthalen-2-yl)-1,3-dihydroimidazole-2-thione;

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: reacting 5,7-difluoro-1,2,3,4-tetrahydronaphthalen-2-ylamine with thiocyanic acid and dihydroxyacetone to give 5-hydroxymethyl-1-(5,7-difluoro-1,2,3,4-tetrahydronaphthalen-2-yl)-1,3-dihydroimidazole-2-thione and

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: reacting 5,7-difluoro-1,2,3,4-tetrahydronaphthalen-2-ylamine with thiocyanic acid and dihydroxyacetone to give 5-hydroxymethyl-1-(5,7-difluoro-1,2,3,4-tetrahydronaphthalen-2-yl)-1,3-dihydroimidazole-2-thione;

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 12 g. of 2-mercapto-4,5-diphenyl-oxazole (m.p. 252°-254°, from methanol; obtainable from 4,5-diphenyl-2-oxazolone and phosphorus pentasulfide in boiling xylene, or by the reaction of benzoin with HSCN) is dissolved in 100 ml. of DMF, and 1.2 g. of NaH is added thereto. The reaction mixture is agitated for 1.5 hours at room temperature. Then, 5.6 ml. of the ethyl ester of bromoacetic acid in 20 ml. of DMF is added dropwise thereto, and the reaction mixture is stirred for 2 hours at 80°. The mixture is then mixed with water and worked up as usual, thus obtaining the ethyl ester of 4,5-diphenyl-2-oxazolyl-mercaptoacetic acid, b.p. 207°-210°/0.1 mm.; m.p. 54°-56° (hexane). is dissolved in 100 ml the reaction mixture is stirred for 2 hours at 80°

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 1-hydroxy-1-phenyl-2-ethyleniminoethane (16.3 g) in dioxan (35 ml) was added dropwise and with stirring at 0° C to an aqueous solution of thiocyanic acid (200 ml of 1N solution). After the addition the mixture was stirred in the cold for 1 hour. It was then heated under reflux for 1 hour and the solution cooled. The desired compound crystallised in 96% yield, m.p. 160° C. After the addition the mixture It was then heated under reflux for 1 hour the solution cooled The desired compound crystallised in 96% yield, m.p. 160° C.