Ammonia → (+-)-1,1'-Binaphthyl-2,2'-diamine

Participants

Reaction Conditions

Reaction Steps

Although it is reported that 2-naphthylamine can be obtained in high yield when 2-naphthol was heated to 150° C. in the presence of concentrated aqueous ammonia and ammonium sulfite for 8 hours, no reaction was observed when the same conditions were subjected to BINOL. When the temperature was increased to 200° C. and more ammonium sulfite was employed, NOBIN was exclusively formed without detectable amounts of BINAM. Thus, by extending the reaction time to 5 days and increasing the amount of ammonium sulfite to 10 equivalents, the starting material disappeared completely. The produced solid was simply filtered and washed with water. A 91% isolated yield of NOBIN was obtained by recrystallization from benzene. Thus, a practical procedure for the synthesis of NOBIN from BINOL in a single-step via a process that can be scaled-up in high yield is provided.

Provenance & Evidence