Patent GB-576340-A (GB)
Title: Improvements in or relating to the manufacture of amine carbonates and to inhalant preparations containing the same
IPC: A61K9/00
Filed: 1944-01-12
Abstract: Carbonates of 1-R-1 amino ethanes, where R is a saturated aliphatic hydrocarbon radical having from 4 to 9 carbon atoms are prepared by reacting the amine with carbon dioxide and water, preferably in the proportions of one-half molecular equivalent each per mole. of amine. The normal carbonate is the main reaction product.  These amine carbonates may be used in inhalers as vasoconstrictors (see Group VI).  The process may be carried out as follows: (1) by passing dry carbon dioxide through a mixture of the amine and water in the above proportions until a one-half molar quantity of the carbon dioxide has been taken up; (2) by passing moist carbon dioxide through the dry amine until the increase in weight corresponds to absorption of the above-stated equivalents of carbon dioxide and water; (3) by passing moist carbon dioxide into a dry solution of the amine in a volatile solvent such as ether until the theoretical increase in weight has occurred as in (2) and then carefully removing the solvent by evaporation; (4) by passing moist carbon dioxide into a solution of moist amine in an oil base such as mineral oil, cottonseed oil, or olive oil with the addition of an essential oil which facilitates said solution, such as menthol, camphor, oil of lavender or oil of rose; alternatively, in this method either the amine or carbon dioxide may be dry, but at least one of them should contain sufficient moisture for the production of the carbonate which is determined by the weight increase as above. The reaction temperature is desirably maintained below 30 DEG  C.  The amino ethanes employed as starting materials and their preparations are described in Specifications 4076/43, 4446/43, 575,677 and 576,943 (as open to public inspection under Sect. 91).  Examples describe the preparation of (1) 2-aminoheptane carbonate by method 1; (2) the same carbonate by method 3; (3) and (4) the carbonates of 2-amino-4-methyl hexane and 2-amino-4-methyl heptane by method 1; (5) 2-amino heptane carbonate by passing dry carbon dioxide into a solution of the amine, water, menthol, oil of rose, and paraffin oil; (6) 2-amino-4-methyl hexane carbonate by passing dry carbon dioxide into a mixture comprising the amine, water, menthol, oil of lavender, and cottonseed oil; and (7) 2-amino-4-methyl heptane carbonate by passing dry carbon dioxide into a solution of the amine, water, menthol, camphor, oil of rose geranium and ethyl oleate.  In examples 5, 6 and 7, peanut oil or lauryl alcohol may replace the oil base used.  In place of menthol and the essential oils, there may be used phenylethyl alcohol, oil of thyme and oil of cedar.  The Specification as open to inspection under Sect. 91 states that the starting materials may also comprise 1-R-1 amino ethanes, where R is an unsaturated aliphatic hydrocarbon radical having 4 to 9 carbon atoms; thus the 2-amino heptane used in the above examples may be replaced by 2-amino heptene or 2-amino-heptine. This subject-matter does not appear in the Specification as accepted.ALSO:Carbonates I-R-I-amino ethanes where R represents a saturated aliphatic hydrocarbon of 4 to 9 carbon atoms (see Group IV) may be used as vasoconstrictors in inhalers.  They may be used as such but are preferably employed in solution in oil bases, such as liquid petrolatum, certain vegetable oils such as cottonseed oil, and esters of fatty acids such as ethyl oleate.  Desirably an essential oil which facilitates the solution of such as menthol, camphor, oil of lavender, or oil of rose, may be present.  In examples are described (1) amine carbonates of 2-aminoheptane, 2-amino-4-methylhexane, and 2-amino-4-methylheptane, all being suitable as inhalers; (2) an inhalant preparation comprising 2-aminoheptane carbonate, menthol, oil of rose and paraffin oil which may be used on cotton pledgets; (3) an inhalant mixture comprising 2-amino-4-methylhexane carbonate, menthol, oil of lavender and cottonseed oil; and (4) an inhalant mixture comprising 2-amino-4-methyl heptane carbonate, menthol, camphor, oil of rose geranium and ethyl oleate.  The oil bases may be replaced by peanut oil or lauryl alcohol, while instead of menthol and the above mentioned essential oils, there may be used in phenylethyl alcohol, oil of thyme, and oil of cedar.  The parent amines are described in Specifications 575,677, 576,943, 4076/43 and 4446/43 (as open to inspection under Section 91).  The Specification as open to inspection under Section 91 includes also the use of 2-amino alkenes and 2-amino alkines, being I-R-I-aminoethanes where R is an unsaturated aliphatic hydrocarbon radical having 4 to 9 carbon atoms; thus the 2-amino heptane used above may be replaced by 2-amino heptene or 2-amino heptine.  This subject matter does not appear in the Specification as accepted.