Sulfuric Acid → 5,11-Dihydro-9-methyl-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one

HRID 2351375Notes

Reaction equation

HRID 2351375 reaction equation
[NH2:1][C:2]1[CH:17]=[C:16]([CH3:18])[CH:15]=[CH:14][C:3]=1[C:4]([NH:6][C:7]1[C:8](Cl)=[N:9][CH:10]=[CH:11][CH:12]=1)=[O:5].ClC1C(N)=CC=CN=1.NC1C=C(C)C=CC=1C(OC)=O.S(=O)(=O)(O)O>S1(CCCC1)(=O)=O.ClCCl.C1(C)C=CC=CC=1>[CH3:18][C:16]1[CH:15]=[CH:14][C:3]2[C:4](=[O:5])[NH:6][C:7]3[CH:12]=[CH:11][CH:10]=[N:9][C:8]=3[NH:1][C:2]=2[CH:17]=1

Participants

8

Reactant 4

HCID 1118Sulfuric AcidHCID 805282-Chloro-3-pyridylamineHCID 11205965Methyl 2-amino-4-methylbenzoateHCID 142099722-amino-N-(2-chloro-pyridin-3-yl)-4-methyl-benzamide

Product 1

HCID 142099755,11-Dihydro-9-methyl-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one

Reagents, catalysts & solvents 3

HCID 1140TolueneSolventHCID 6344DichloromethaneSolventHCID 31347SulfolaneSolvent

Conditions

Temperature
80 °C

Procedure

127.0 g (0.485 mol) of 2-amino-N-(2-chloro-pyridin-3-yl)-4-methyl-benzamide (m.p. 150°-152° C.) prepared analogously to Example A from 2-chloro-3-amino-pyridine and methyl 2-amino-4-methyl-benzoate (see F. Mayer and R. Schulze, Ber. Dtsch. Chem. Ges. 58, 1465 [1925]) were suspended in 500 ml of sulpholane and after the addition of 1.4 ml of conc. sulphuric acid the suspension was heated for 3 hours to 130° C. with stirring. It was then left to cool to 80° C., 500 ml of toluene were added and the mixture was left to stand overnight at ambient temperature. The crystals formed were suction filtered, suspended in 0.75 liters of dichloromethane, suction filtered once more and thoroughly washed with dichloromethane. After drying in a circulating air dryer, 70.2 g (64% of theory) of very slightly yellow crystals were obtained, m.p. 286°-288° C., which were further reacted without any further purification.

Workup

  1. temperaturewas heated for 3 hours to 130° C.
  2. waitIt was then left
  3. waitthe mixture was left
  4. customThe crystals formed
  5. filtrationsuction filtered once more
  6. washthoroughly washed with dichloromethane
  7. customAfter drying in a circulating air dryer, 70.2 g (64% of theory) of very slightly yellow crystals
  8. customwere obtained
  9. customm.p. 286°-288° C., which were further reacted without any further purification

Sources & evidence

ORD record
ord-37ea345e4eb54e44807a8850e3926268
Source dataset
uspto-grants-1989_10
Patent number
US04873236

Reaction notes

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