Phosphonic acid,P,P'-(4-amino-1-hydroxybutylidene)bis-

The IUPAC name of Alendronate is (4-amino-1-hydroxy-1-phosphonobutyl)phosphonic acid. With the CAS registry number 66376-36-1, it is also named as Acide alendronique. The classification codes are Bone Density Conservation Agents; Reproductive Effect. It is white fine powder which is soluble in water, easily soluble in ethanol, and almost insoluble in chloroform. When heated to decomposition it emits toxic vapors of NO_x and PO_x. Besides, this chemical is DBPA resorption inhibitors which is mainly used for the treatment of osteoporosis. Additionally, it should be sealed in the container and stored in the cool and dry place.

The other characteristics of this product can be summarized as: (1)ACD/LogP: -3.52; (2)# of Rule of 5 Violations: 1; (3)ACD/LogD (pH 5.5): -7.15; (4)ACD/LogD (pH 7.4): -7.92; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 1; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 8; (10)#H bond donors: 7; (11)#Freely Rotating Bonds: 7; (12)Polar Surface Area: 103.15 Å²; (13)Index of Refraction: 1.593; (14)Molar Refractivity: 45.5 cm³; (15)Molar Volume: 134.1 cm³; (16)Surface Tension: 119.3 dyne/cm; (17)Enthalpy of Vaporization: 104.87 kJ/mol; (18)Vapour Pressure: 8.72E-18 mmHg at 25°C; (19)Rotatable Bond Count: 5; (20)Exact Mass: 249.016725; (21)MonoIsotopic Mass: 249.016725; (22)Topological Polar Surface Area: 161; (23)Heavy Atom Count: 14; (24)Complexity: 257.

Preparation of Alendronate:  Adding 1mol 4-aminobutyric acid to 95 °C melting 1.5mol phosphoric acid. And then dropping 2mol phosphorus trihalides in 60min. When the reactants is hardening, heat 3h more. Then adding 300ml water to hydrolysis. After cooling, pouring into 1500ml methanol. Collecting the precipitate to get the product.

People can use the following data to convert to the molecule structure. 
1. SMILES:O=P(O)(O)C(O)(CCCN)P(=O)(O)O
2. InChI:InChI=1/C4H13NO7P2/c5-3-1-2-4(6,13(7,8)9)14(10,11)12/h6H,1-3,5H2,(H2,7,8,9)(H2,10,11,12)
3. InChIKey:OGSPWJRAVKPPFI-UHFFFAOYAU