# Formulation of Boron Encapsulated Smart Nanocapsules for Targeted Drug Delivery to the Brain
## 3 Results
### Synthetic Methods
#### 3.1.2 Synthesis of (3-Carboranylpropyl) (Triphenyl phosphonium) Bromide (2)  
The progress of the reaction for the formation of Compound 2 (Figure 5) was examined via TLC (Silica plates) using hexane as the mobile phase. The R\({}_{\rm f}\) value obtained was 0.42. The yield obtained where 85%, with the product having a fine texture and being yellow in colour. The purified product was analysed using a variety of spectroscopic methods, and all data are presented below. Figure 4: Structure of but-3-yn-1-yl (triphenyl phosphonium) bromide (1). Figure 5: Structure of (3-carboranylpropyl) (triphenyl phosphonium) bromide (2). \({}^{13}\)C NMR: (3-carboxarylpropyl) (triphenyl phosphonium) bromide (2); (AV400 with CDCl\({}_{3}\)): 13-25 ppm (aliphatic C-C, 7, 8), 40 ppm (carborane B-CH, 9), 125.7 ppm (aromatic C-C, 3, 4, 5), 128.5 ppm (aromatic C-C, 2, 6), 135.3 ppm (aromatic C-C, 1). FT-IR: (3-carboxarylpropyl) (triphenyl phosphonium) bromide (2): 3000-3100 cm\({}^{-1}\) (C-H stretch, aromatic (-CH), weak, 1-6), 2300-2600 cm\({}^{-1}\) (B-H stretch, medium, 9), 1500-1600 cm\({}^{-1}\) (C=C stretch, aromatic C=C, weak, 1-6), 1430-1470 cm\({}^{-1}\) (C-H bend, methylene (-CH\({}_{2}\)), medium, 7-8), 1050-1150 cm\({}^{-1}\) (B-H deformation, medium, 9), 800-860 cm\({}^{-1}\) (B-H vibration, medium, 9). 1.3 Synthesis of But-3-yn-1-yl N\({}^{9}\),N\({}^{9}\)-Diethyl-9H-benzo[\(a\)]phenoxazine-5,9-diamine Bromide (3)  
The formation of the intermediate to form Compound 3 (Figure 6) allows for the functionalisation of the amine group with 1-bromo-3-butyne. Once this is formed, the DLC to the carborane dye can be formed in situ. The formation of compound 3 was analysed through TLC (silica plates) using hexane as the mobile phase. The R\({}_{\rm f}\) value obtained was 0.31. But-3-yn-1-yl (N\({}^{9}\),N\({}^{9}\)-diethyl-9H-benzo[\(a\)]phenoxazine-5,9-diamine) was analysed using a variety of spectroscopic methods, and all data are presented below. \({}^{1}\)H NMR: But-3-yn-1-yl (N\({}^{9}\),N\({}^{9}\)-diethyl-9H-benzo[\(a\)]phenoxazine-5,9-diamine) bromide (AV400 with DMSO): 6.2-8 ppm (aromatic C-H, multiplet, 7, 10, 11, 12, 13, 15, 17, 18), 3.5 ppm (amine (NH), multiplet, 19), 2.6 ppm (aliphatic C-H, multiplet, 21), 2.5 ppm (aliphatic C-H, multiplet, 20), 2.1 ppm (alkyne CH, singlet, 23), 1-1.3 ppm (aliphatic C-H, multiplet, 25, 26, 27, 28). FT-IR: But-3-yn-1-yl (N\({}^{9}\),N\({}^{9}\)-diethyl-9H-benzo[\(a\)]phenoxazine-5,9-diamine) bromide: 2950-3100\({}^{-1}\) (C-H stretch, aromatic C-H, broad weak, 7, 10, 11, 12, 13, 15, 17, 18, 20, 21, 25, 26, 27, 28), 1643 cm\({}^{-1}\) (alkyne stretch, medium, 22, 23), 1532 cm\({}^{-1}\) (amine stretch, medium, 19). 1.4 Synthesis of (3-Carboranylpropyl) (N\({}^{9}\),N\({}^{9}\)-Diethyl-9H-benzo[\(a\)]phenoxazine-5,9-diamine) Bromide (4)  
The progress of the reaction for compound 4 (Figure 7) was analysed through TLC (silica plates) using hexane as the mobile phase. The R\({}_{\rm f}\) value obtained was 0.4. The yields obtained were around 85%, with the product having a fine texture and dark blue in colour. Figure 6: Structure of but-3-yn-1-yl (N\({}^{9}\),N\({}^{9}\)-diethyl-9H-benzo[\(a\)]phenoxazine-5,9-diamine) bromide (3). \({}^{1}\)H NMR: (3-carboranylpropyl)-(N\({}^{9}\),N\({}^{9}\)-diethyl-9H-benzo[\(a\)]phenoxazine-5,9-diamine) bromide (AV400 with DMSO): 6.2-8 ppm (aromatic C-H, multiplet, 7, 10, 11, 12, 13, 15, 17, 18), 3.3-3.5 ppm (amine (NH), multiplet, 19), 0.8-1 ppm (borohydride, B-H, multiplet, 22), 1.8-22 ppm (aliphatic C-H, multiplet, 20), 2.5 ppm (aliphatic C-H, multiplet, 21). \({}^{11}\)B NMR: (3-carboranylpropyl)-(N\({}^{9}\),N\({}^{9}\)-diethyl-9H-benzo[\(a\)]phenoxazine-5,9-diamine) bromide (AV400 with DMSO): \(-\)40 ppm (B-H bond), \(-\)20 ppm (C-H bond).