Some common heterocyclic compound, 1575-37-7, name is 4-Bromobenzene-1,2-diamine, molecular formula is C6H7BrN2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 1575-37-7
General procedure: A solution of 10 mmol of the appropriate benzene-1,2-diamine in3.5 mL of acetic acid (AcOH) and 1 mL of water was cooled to 0-5 C,followed by the addition of 15 mmol of sodium nitrite in 2 mL ofwater. The mixture was stirred for 2 h at room temperature. Afterthe completion of the reaction, a solventwas evaporated and the residuewasco-evaporatedwith toluene (3 ¡Á 20mL). The crude productwas partitioned between water (20 mL) and ethyl acetate (20 mL),the organic phase was washed with the saturated solution of sodiumhydrogen carbonate and dried overmagnesiumsulfate (MgSO4). Theproducts were purified by crystallization from nitromethane and/orby column chromatography on silica gel using a chloroform – methanol97:3-95:5 v/v mixture as eluent. Reaction products were analyzedby use of mass-spectrometry (Waters Q-TOF Premier MassSpectrometer) and NMR spectroscopy (Varian INOVA 500 Spectrometer,see Supp. Fig. 1). Purity of the products was assessed using internalstandard quantitative NMR method (qNMR) [49]. It shouldbe noted that the formal qNMR-derived purity determined for 4-BrBt, 4-ClBt, 5,6-Cl2Bt and 5,6-Br2Bt increased significantly upon additiona small amount of water to the DMSO solution, which increasedproton exchange rates. This observation indicates that thenuclear relaxation process accompanying protomeric equilibrium(generally N1-H and N3-H forms predominates) significantly contributeto the obtained NMR spectra, the best proof of which is thestrong broadening of the H-7 resonance line in 4-BrBt and 4-ClBt(Supp. Fig. 1A,B).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1575-37-7, its application will become more common.
Reference:
Article; Szymaniec-Rutkowska, Anna; Bugajska, Ewa; Kasperowicz, S?awomir; Mieczkowska, Kinga; Maciejewska, Agnieszka M.; Pozna?ski, Jaros?aw; Journal of Molecular Liquids; vol. 293; (2019);,
Bromide – Wikipedia,
bromide – Wiktionary