These common heterocyclic compound, 6134-56-1, name is 6-Bromo-1,2,3,4-tetrahydronaphthalene, its 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. Safety of 6-Bromo-1,2,3,4-tetrahydronaphthalene
[-BUTYL] lithium (9.6 ml of 2. [5M] solution in hexane) was added [DROPWIS OVER] 30 minutes to a stirred solution of [5-BROM-1,] 2,3, 4-tetrahydronaphthalene in mixture with its regioisomer [6-BROM-1,] 2,3, 4-tetrahydronaphthalene (5 g) in dry THF (125 ml) and hexane (35 ml) [AT-70 C,] stirring was continued at-78 C for 30 minutes, carbon dioxide gas was bubbled through the mixture at-70 C until no further exotherm was evident, carbon dioxide gas addition was continued for a further 10 minutes as the reaction was allowed to warm to ambient temperature, the mixture was poured into 2M aqueous hydrochloric acid (100 ml) and the resulting mixture was extracted with diethyl ether (3 x 50 ml). The combined organic extracts were washed with water (100 ml) and were then extracted with 10% aqueous sodium carbonate solution (3 x 50 ml). The combined aqueous carbonate extracts were acidified carefully by addition of 2M hydrochloric acid to adjust the pH to pH 1. The resulting mixture was extracted with diethyl ether (3 x 50 ml), the combined organic extracts were washed with water (50 ml) and dried [(MGS04)] before solvent was removed by evaporation [IN VACUO TO] give the crude product in 64% yield comprising a mixture [OF REGIOISOMERS] of 5,6, 7,8-tetrahydronaphthalene carboxylic acid. This mixture was purified by repeated recrystallisation from ethyl acetate to give 5,6, 7,8- tetrahydronaphthalene-2-carboxylic acid as crystallised solid in 93% purity along with 5,6, 7, [8-TETRAHYDRONAPHTHALENE-1-CARBOXYLIC] acid as the major component present in the crystallisation mother liquors.
The synthetic route of 6-Bromo-1,2,3,4-tetrahydronaphthalene has been constantly updated, and we look forward to future research findings.
Reference:
Patent; ASTRAZENECA AB; WO2004/792; (2003); A1;,
Bromide – Wikipedia,
bromide – Wiktionary