Digestion of impure alumina with sulfuric acid dissolves all constituents except silica. Resulting sulfates, produced from contaminants in the impure alumina, remain in solution at approximately 90 C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate. Addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide. Carbon monoxide reduces the ferrous oxide to metallic iron. Further oxalic acid addition precipitates magnesium oxalate which is thermally decomposed to magnesium oxide.

Digestion of impure alumina with sulfuric acid dissolves all constituents except silica. Resulting sulfates, produced from contaminants in the impure alumina, remain in solution at approximately 90 C. Hot filtration separates silica. Solution flow over metallic iron reduces ferric sulfate to ferrous sulfate. Controlled ammonia addition promotes hydrolysis and precipitation of hydrated titania from titanyl sulfate that is removed by filtration. Addition of ammonium sulfate forms ferrous ammonium sulfate and ammonium aluminum sulfate solutions. Alum is preferentially separated by crystallization. Addition of ammonium bicarbonate to ammonium alum solution precipitates ammonium aluminum carbonate which may be heated to produce alumina, ammonia, and carbon dioxide. The remaining iron rich liquor also contains magnesium sulfate. Addition of oxalic acid generates insoluble ferrous oxalate which is thermally decomposed to ferrous oxide. Carbon monoxide reduces the ferrous oxide to metallic iron. Further oxalic acid addition precipitates magnesium oxalate which is thermally decomposed to magnesium oxide.

A gas generant composition for passive inflatable restraint systems (e.g., airbags) for automobiles is provided that comprises a melamine oxalate compound. The gas generant may be a cool burning gas generant composition that comprises a melamine oxalate compound, a co-fuel, such as guanidine nitrate, and an oxidizer, such as basic copper nitrate. The gas generant composition has advantageous combustion properties, including a maximum flame temperature at combustion (T.sub.c) of about 1700 K (1,427 C.), a linear burn rate of about 18 mm per second at a pressure of about 10 megapascals (MPa), a gas yield of the gas generant composition of about 5.7 moles/100 cm.sup.3, and a linear burn rate pressure exponent of about 0.35.

A gas generant composition for passive inflatable restraint systems (e.g., airbags) for automobiles is provided that comprises a melamine oxalate compound. The gas generant may be a cool burning gas generant composition that comprises a melamine oxalate compound, a co-fuel, such as guanidine nitrate, and an oxidizer, such as basic copper nitrate. The gas generant composition has advantageous combustion properties, including a maximum flame temperature at combustion (T.sub.c) of about 1700 K (1,427 C.), a linear burn rate of about 18 mm per second at a pressure of about 10 megapascals (MPa), a gas yield of the gas generant composition of about 5.7 moles/100 cm.sup.3, and a linear burn rate pressure exponent of about 0.35.

It relates to improved processes of preparing 5R-[(benzyloxy) amino] piperidine-2S-carboxylate and oxalate thereof. In the present invention, L-glutamic acid or L-glutamic acid sodium salt as the starting material is reacted with chloroactic acid under an alkaline condition via a substitution reaction to obtain compound III; then, compound III is reacted with alcohol in the presence of acid reagent via esterification reaction to obtain compound IV; under the action of strong base, compound IV is subjected to intramolecular condensation into ring, hydrolysis-decarboxylation, and esterification to obtain compound V; compound V is condensed with benzyloxy amine hydrochloride salt in the presence of alkaline to obtain compound VI; compound VI is subjected to reduction and chiral resolution to obtain 5R-[(benzyloxy) amino] piperidine-2S-carboxylate oxalate (IIb) which is then neutralized to obtain 5R-[(benzyloxy) amino] piperidine-2S-carboxylate (IIa).

It relates to improved processes of preparing 5R-[(benzyloxy) amino] piperidine-2S-carboxylate and oxalate thereof. In the present invention, L-glutamic acid or L-glutamic acid sodium salt as the starting material is reacted with chloroactic acid under an alkaline condition via a substitution reaction to obtain compound III; then, compound III is reacted with alcohol in the presence of acid reagent via esterification reaction to obtain compound IV; under the action of strong base, compound IV is subjected to intramolecular condensation into ring, hydrolysis-decarboxylation, and esterification to obtain compound V; compound V is condensed with benzyloxy amine hydrochloride salt in the presence of alkaline to obtain compound VI; compound VI is subjected to reduction and chiral resolution to obtain 5R-[(benzyloxy) amino] piperidine-2S-carboxylate oxalate (IIb) which is then neutralized to obtain 5R-[(benzyloxy) amino] piperidine-2S-carboxylate (IIa).

Provided herein are novel solid forms of each of four compounds: (1) heptadecan-9-yl 8-((2-hydroxyethyl)amino)octanoate (Compound 1), (2) heptadecan-9-yl 8-((2-hydroxyethyl)(6-oxo-6-(undecyloxy)hexyl)amino)octanoate (Compound 2), (3) heptadecan-9-yl 8-((2-hydroxyethyl)(8-(nonyloxy)-8-oxooctyl)amino)octanoate (Compound 3), and (6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate (MC3), and related compositions and methods.

Provided herein are novel solid forms of each of four compounds: (1) heptadecan-9-yl 8-((2-hydroxyethyl)amino)octanoate (Compound 1), (2) heptadecan-9-yl 8-((2-hydroxyethyl)(6-oxo-6-(undecyloxy)hexyl)amino)octanoate (Compound 2), (3) heptadecan-9-yl 8-((2-hydroxyethyl)(8-(nonyloxy)-8-oxooctyl)amino)octanoate (Compound 3), and (6Z,9Z,28Z,31Z)-heptatriaconta-6,9,28,31-tetraen-19-yl 4-(dimethylamino)butanoate (MC3), and related compositions and methods.

The gas generating agent of the present invention comprises an oxalic acid salt of an aminoguanidine compound represented by general formula (1) below.

##STR00001##

The gas generating agent of the present invention comprises an oxalic acid salt of an aminoguanidine compound represented by general formula (1) below.

##STR00001##