Benzoyl chloride → 1-Benzoyl-1,2,3,4-tetrahydrobenzo[c]-1,5-naphthyridine

HRID 1906458Notes

Reaction equation

HRID 1906458 reaction equation
[NH:1]1[CH2:10][CH2:9][CH2:8][C:7]2[N:6]=[CH:5][C:4]3[CH:11]=[CH:12][CH:13]=[CH:14][C:3]=3[C:2]1=2.[C:15](Cl)(=[O:22])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>[OH-].[K+]>[C:15]([N:1]1[CH2:10][CH2:9][CH2:8][C:7]2[N:6]=[CH:5][C:4]3[CH:11]=[CH:12][CH:13]=[CH:14][C:3]=3[C:2]1=2)(=[O:22])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

4

Reactant 2

HCID 7412Benzoyl chlorideHCID 138234741,2,3,4-Tetrahydrobenzo[c]-1,5-naphthyridine

Product 1

HCID 138234771-Benzoyl-1,2,3,4-tetrahydrobenzo[c]-1,5-naphthyridineYield 86.8%

Reagents, catalysts & solvents 1

HCID 14797Potassium HydroxideSolvent

Procedure

A stirred solution of 1,2,3,4-tetrahydrobenzo[c]-1,5-naphthyridine (4.6 g) and KOH-dried pyridine (50 ml) was treated dropwise over one minute with benzoyl chloride (8.4 g). A crystalline precipitate formed. The stirred suspension was heated (steam bath) for 1.25 hours and the resultant solution was then stirred overnight at ambient temperature during which a crystalline precipitate formed. The mixture was decanted into water (200 ml), basified with 10% sodium hydroxide solution and extracted with dichloromethane. The dried (Na2SO4) organic phase was filtered and evaporated to dryness (7.47 g of crystalline solid). Recrystallization from toluene afforded 6.25 g of crystals, m.p. 208.5°-210.5° C. An aliquot of the material (4.81 g) was further purified by preparative HPLC (silica gel, eluted with ethyl acetate). The appropriate fractions were concentrated and the residue was recrystallized from toluene (100 ml) to give 4.14 g of crystals, m.p. 208°-210° C.

Workup

  1. customA crystalline precipitate formed
  2. temperatureThe stirred suspension was heated (steam bath) for 1.25 hours
  3. customformed
  4. customThe mixture was decanted into water (200 ml)
  5. extractionextracted with dichloromethane
  6. dry with materialThe dried (Na2SO4) organic phase
  7. filtrationwas filtered
  8. customevaporated to dryness (7.47 g of crystalline solid)
  9. customRecrystallization from toluene

Sources & evidence

ORD record
ord-91451778c1cd450daed3cea5d035c220
Source dataset
uspto-grants-1987_03
Patent number
US04652567

Reaction notes

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