Patent GB-403451-A (GB)
Title: Improvements in the manufacture of terpenes
IPC: C07C5/29
Filed: 1932-07-01
Abstract: In the process of the parent Specification for the catalytic conversion of nopinene and pinene into isomeric terpenes, there are employed as catalysts inorganic acids, or inorganic or inorganic-organic complex acids which do not combine with the terpenes in question or do so only slowly and which are produced from their neutral or acid salts with volatile or non-volatile bases in such a manner that the base in question is only incompletely removed. The preparation of the catalysts may be effected either by treating the salts in the cold or hot with a quantity of acid insufficient for complete removal of the base, or, in the case of salts with volatile bases, by incompletely expelling these bases by heating alone or in a current of gas or steam.  If in the case of volatile bases too much water of hydration is removed in the preparation of the catalysts, they may be hydrated again to the optimum stage by heating with water, if necessary under pressure.  The process is also applicable to the regeneration of used catalysts.  In examples of the preparation of the catalysts: (1) ammonium tungstate is suspended in water and treated with hydrochloric acid on a boiling water bath to produce tungstic acid containing 1.5 per cent of ammonia; (2) ammonium tungstate is heated to 290--300 DEG  C. with the passage of superheated steam until the product contains 1--1.5 per cent of ammonia; (3) a solution of tungstic acid in aqueous ammonia is allowed to drop into nitric acid at 100 DEG  C. yielding tungstic acid containing 0.85 per cent of ammonia; (4) tungstic acid is dissolved in caustic soda solution and hydrochloric acid is added, the product containing 0.3 per cent of sodium; (5) ammonium vanadate is treated at 320--325 DEG  C. with the passage of steam heated to the same temperature until the ammonia is practically completely split off and the product is heated with water at 240 DEG  C. under pressure; (6) ammonium molybdate is treated at 300--310 DEG  C. with the passage of steam heated to the same temperature until the ammonia is practically completely split off and the product is heated with water at 250 DEG  C. under pressure; (7) ammonium molybdate is heated to 280 DEG  C. with the passage of superheated steam until the product contains about 3 per cent of ammonia; (8) sodium titanate is treated with 95 per cent of the amount of glacial acetic acid required for complete removal of the sodium.  The Specification as open to inspection under Sect. 91 contains additional examples in which: (1) sodium water glass solution is treated with hydrochloric acid until phenolphthalein is decolorized but litmus not yet reddened; (2) the product obtained by dissolving phosphoric acid and boric acid in aqueous ammonia and evaporating the solution on the water bath is heated to 340--345 DEG  C. with the passage of steam heated to the same temperature and the product is heated with water under pressure. This subject-matter does not appear in the Specification as accepted.ALSO:In the process of the parent Specification for the catalytic conversion of nopinene and pinene into isomeric terpenes, there are employed as catalysts inorganic acids, or inorganic or inorganic-organic complex acids which do not combine with the terpenes in question or do so only slowly and which are produced from their neutral or acid salts with volatile or non-volatile bases in such a manner that the base in question is only incompletely removed.  The preparation of the catalysts may be effected either by treating the salts in the cold or hot with a quantity of acid insufficient for complete removal of the base, or, in the case of salts with volatile bases, by incompletely expelling these bases by heating alone or in a current of gas or steam.  If in the case of volatile bases too much water of hydration is removed in the preparation of the catalysts, they may be hydrated again to the optimum stage by heating with water, if necessary under pressure. The process is also applicable to the regeneration of used catalysts. In examples of the preparation of the catalysts: (1) ammonium tungstate is suspended in water and treated with hydrochloric acid on a boiling water bath to produce tungstic acid containing 1.5 per cent of ammonia; (2) ammonium tungstate is heated to 290--300 DEG  C. with the passage of superheated steam until the product contains 1--1.5 per cent of ammonia; (3) a solution of tungstic acid in aqueous ammonia is allowed to drop into nitric acid at 100 DEG  C. yielding tungstic acid containing 0.85 per cent of ammonia; (4) tungstic acid is dissolved in caustic soda solution and hydrochloric acid is added, the product containing 0.3 per cent of sodium; (5) ammonium vanadate is treated at 320--325 DEG  C. with the passage of steam heated to the same temperature until the ammonia is practically completely split off and the product is heated with water at 240 DEG  C. under pressure; (6) ammonium molybdate is treated at 300--310 DEG  C. with the passage of steam heated to the same temperature until the ammonia is practically completely split off and the product is heated with water at 250 DEG  C. under pressure; (7) ammonium molybdate is heated to 280 DEG  C. with the passage of superheated steam until the product contains about 3 per cent of ammonia; (8) sodium titanate is treated with 95 per cent of the amount of glacial acetic acid required for complete removal of the sodium.  The Specification as open to inspection under Sect. 91 contains additional examples in which: (1) sodium water glass solution is treated with hydrochloric acid until phenolphthalein is decolorized but litmus not yet reddened; (2) the product obtained by dissolving phosphoric acid and boric acid in aqueous ammonia and evaporating the solution on the water bath is heated to 340--345 DEG  C. with the passage of steam heated to the same temperature and the product is heated with water under pressure. This subject-matter does not appear in the Specification as accepted.