1,1'-Biphenyl, mixt. with 1,1'-oxybis(benzene) → 1,5-Naphthyridine

HRID 526074Notes

Reaction equation

HRID 526074 reaction equation
Cl[C:2]1[CH:7]=[CH:6][C:5]([NH2:8])=[CH:4][N:3]=1.C(OCC)(OCC)OCC.[CH:19]1[CH:24]=CC(C2C=CC=CC=2)=C[CH:20]=1.C1C=CC(OC2C=CC=CC=2)=CC=1>>[N:3]1[C:4]2[C:5](=[N:8][CH:20]=[CH:19][CH:24]=2)[CH:6]=[CH:7][CH:2]=1

Participants

4

Reactant 3

HCID 246701,1'-Biphenyl, mixt. with 1,1'-oxybis(benzene)HCID 31214Ethyl orthoformateHCID 793055-Amino-2-chloropyridine

Product 1

HCID 1360701,5-Naphthyridine

Procedure

The 2-chloro-5-aminopyridine A is converted by heating in the presence of ester B and triethyl orthoformate to the condensation product C as a mixture of olefin isomers (Scheme 1). Various esters that are commercially available, known in the literature or prepared using known literature procedures are applicable to the reaction. Intermediate C is added to hot Dowtherm™ A to facilitate the ring closure and to afford the 1,5-naphthyridine D. Treatment of D with phosphorus oxychloride affords the key intermediate E (Scheme 1).

Workup

  1. customprepared
  2. customare applicable to the reaction

Sources & evidence

ORD record
ord-fa492946de4641428c891e980e3f02ec
Source dataset
uspto-grants-2016_05
Patent number
US09345709B2

Reaction notes

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