Chlorosuccinimide → Benzimidazole

Compounds of Formula (I) can be formed as shown in Scheme I. The thiols (L=S) or phenols (L=O) (i) can be alkylated using standard alkylating conditions (Cy3COC(R1R2)—X (ii), X=leaving group, such as halo (Br, Cl, I or mesylate) or Mitsunobu conditions (e.g., Cy3COC(R1R2)—X, where X═OH (ii), DEAD, Ph3P) to afford thioether or ether derivatives (iii), respectively. Cyclization in situ or upon heating can afford imine (iv) which upon treatment with a Grignard reagent of formula R4—MgX1 (X1=halo) and reduction of the nitro group (e.g., H2 Pd/C or Fe) to give an amine (v). Compounds (v) can either be reacted with carbonyldiamidazole or phosgene to form an urea and then halogenated with N-chlorosuccinimide, N-bromosuccinimide or N-iodosuccinimide to give tricyclic halide (vi) where X═Cl, Br or I or halogenated first and then reacted with carbonyldiamidazole or phosgene to form an urea and give tricyclic halide (vi). Compound (vi) can be alkylated (e.g., R6—X, where X=halo (X═Br, Cl, or I) and a base, such as triethylamine, NaH or Na2CO3; or under Mitsunobu conditions) to afford the tetrasubstituted urea (vii). Finally, the halo group of (vii) can be coupled to M-Cy1, where M is a boronic acid, boronic ester or an appropriately substituted metal (e.g., Cy1-M is Cy1-B(OH)2, Cy1-Sn(Bu)4, or Zn-Cy1), under standard Suzuki conditions or standard Stille conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0) and a base (e.g., a bicarbonate or carbonate base) or standard Negishi conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0), to give a derivative of Formula (I) (viii) wherein R5 is ═O. Alternatively, M-Cy1 can be an amine containing heterocycle (where M is H and is attached to the amine nitrogen of the heterocycle Cy1) with coupling to compound (vii) being performed by heating with a base or under Buchwald conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0) and a base (e.g., an alkoxide base)) to give a derivative of Formula (I) (viii). Alternatively, urea (vi) can be coupled to M-Cy1, where M is a boronic acid, boronic ester or an appropriately substituted metal (e.g., Cy1-M is Cy1-B(OH)2, Cy1-Sn(Bu)4, or Zn-Cy1), under standard Suzuki conditions or standard Stille conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0) and a base (e.g., a bicarbonate or carbonate base) or standard Negishi conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0), to give a derivative of Formula (I) (ix) which can be alkylated (e.g., R6—X, where X=halo (X═Br, Cl, or I) and a base, such as triethylamine, NaH or Na2CO3; or under Mitsunobu conditions) to afford the tetrasubstituted urea of Formula (I) (viii). Alternatively, urea (vi) can be converted to the 2-halo-imidazole, such as Cl upon treatment with POCl3, and then treated with an amine (HNRR) to give benzoimidazole (x) where R5═NRR. Benzoimidazole (x) can then be coupled to M-Cy1, where M is a boronic acid, boronic ester or an appropriately substituted metal (e.g., Cy1-M is Cy1-B(OH)2, Cy1-Sn(Bu)4, or Zn-Cy1), under standard Suzuki conditions or standard Stille conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0) and a base (e.g., a bicarbonate or carbonate base) or standard Negishi conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0), to give a derivative of Formula (I) (xi). M-Cy1 can be an amine containing heterocycle (where M is H and is attached to the amine nitrogen of the heterocycle Cy1) with coupling to compound (x) being performed by heating with a base or under Buchwald conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0) and a base (e.g., an alkoxide base)) to give a derivative of Formula (I) (xi). Alternatively, urea (ix) can be converted to the 2-halo-imidazole, such as Cl upon treatment with POCl3, and then treated with an amine (HNRR) to give benzimidazole (xi) where R5═NRR or the chloride derivative can be coupled to M-R5, where M is a boronic acid, boronic ester or an appropriately substituted metal (e.g., R5-M is R5—B(OH)2, R5—Sn(Bu)4, or Zn—R5), under standard Suzuki conditions or standard Stille conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0) and a base (e.g., a bicarbonate or carbonate base) or standard Negishi conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0), to give a derivative of Formula (I) (xi). M-Cy1 can be an amine containing heterocycle (where M is H and is attached to the amine nitrogen of the heterocycle Cy1) with coupling to the halide of (ix) being performed by heating with a base or under Buchwald conditions (e.g., in the presence of a palladium(0) catalyst, such as tetrakis(triphenylphosphine)palladium(0) and a base (e.g., an alkoxide base)) to give a derivative of Formula (I) (xi). Amino compound (v) can either be treated with an ortho-ester, such as R5C(OEt)3, or an aldehyde R5CHO and NaHSO3 to give a benzimidazole which can be halogenated with N-chlorosuccinimide, N-bromosuccinimide or N-iodosuccinimide to give halo-benzimidazole (x), where X═Cl, Br, or I, or these two steps can be run in the opposite order to give the same benzimidazole (x) which can be further converted to compounds of Formula (I) (xi) as previously described above.

ORD record

ord-3e0faa7405ba449e8ee10b511abe73e3

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09227985B2