Cl.[CH:2]1([O:7][C:8]2[CH:9]=[C:10]([CH:12]=[CH:13][C:14]=2[O:15][CH3:16])[NH2:11])[CH2:6][CH2:5][CH2:4][CH2:3]1.[N:17]([O-])=O.[Na+].[F:21][B-:22]([F:25])([F:24])[F:23].[Na+]>O>[F:21][B-:22]([F:25])([F:24])[F:23].[CH:2]1([O:7][C:8]2[CH:9]=[C:10]([N+:11]#[N:17])[CH:12]=[CH:13][C:14]=2[O:15][CH3:16])[CH2:3][CH2:4][CH2:5][CH2:6]1
A stirred solution of concentrated hydrochloric acid (1.7 mL) in water (5 mL) from 0° C. and 5° C. is treated with 3-cyclopentyloxy-4-methoxyaniline (0.83 g), followed by a solution of sodium nitrite (0.29 g) in water (0.6 mL), at such a rate that the temperature remains from 0° C. and 5° C. The resulting solution is stirred for a further 10 minutes, while keeping the temperature below 5° C. The stirred solution, while still maintained at below 5° C., is then treated dropwise with a solution of sodium tetrafluoroborate (0.88 g) in water (1.8 mL). The resulting precipitate is filtered off, washed with cold water (3 mL) and dried in vacuo, to give 3-cyclopentyloxy-4-methoxyphenyldiazonium tetrafluoroborate (1.24 g) in the form of a gray solid, m.p. 120° C.
Loading…
