Hydrochloric Acid → (S)-7-Chloro-3-(pyrid-3-ylimino)-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinoline

HRID 461818Notes

Reaction equation

HRID 461818 reaction equation
N([O-])=O.[Na+].N[C:6]1[CH:7]=[CH:8][C:9]2[CH2:10][C@H:11]3[CH2:18][S:17][C:16](=[N:19][C:20]4[CH:21]=[N:22][CH:23]=[CH:24][CH:25]=4)[N:12]3[CH2:13][C:14]=2[CH:15]=1.[ClH:26]>O>[Cl:26][C:6]1[CH:7]=[CH:8][C:9]2[CH2:10][C@H:11]3[CH2:18][S:17][C:16](=[N:19][C:20]4[CH:21]=[N:22][CH:23]=[CH:24][CH:25]=4)[N:12]3[CH2:13][C:14]=2[CH:15]=1

Participants

5

Reactant 3

HCID 313Hydrochloric Acid2×HCID 22800662(S)-7-amino-3-(pyrid-3-ylimino)-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinolineHCID 23668193Sodium Nitrite

Product 1

HCID 22800657(S)-7-Chloro-3-(pyrid-3-ylimino)-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinoline

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

A solution of sodium nitrite (3.1 g.) in distilled water (10 cc.) is added slowly to a solution, at 0° C., of (S)-7-amino-3-(pyrid-3-ylimino)-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinoline (13 g.) in 4N hydrochloric acid (25 cc.). The mixture is stirred for 15 minutes at 0° C., and the solution obained is then added to a suspension of cuprous chloride (6 g.) in concentrated hydrochloric acid (d = 1.18; 25 cc.). The mixture is allowed to return to 20° C., and is then heated for 30 minutes at 70° C. After cooling to 20° C., distilled water (200 cc.), methylene chloride (250 cc.) and then N sodium hydroxide solution (100 cc.) are added. After filtration, the organic phase is recovered by decanting and is dried over magnesium sulphate, filtered and concentrated to dryness at 40° C., under reduced pressure (20 mm.Hg). The residue obtained is purified by chromatography on silica gel (200 g.) contained in a column of 3 cm. diameter, elution being carried out with methylene chloride containing 1% v/v of methanol (5,000 cc.), and 1 litre fractions being collected. Fractions 2 to 4 are combined and then concentrated to dryness. The residue obtained is recrystallised from a mixture of isopropanol (70 cc.) and heptane (100 cc.). (S)-7-Chloro-3-(pyrid-3-ylimino)-1,5,10,10a-tetrahydrothiazolo[3,4-b]isoquinoline (5.5 g.), melting at 125° C., is thus obtained.

Workup

  1. customto return to 20° C.
  2. temperatureis then heated for 30 minutes at 70° C
  3. temperatureAfter cooling to 20° C.
  4. distillationdistilled water (200 cc.), methylene chloride (250 cc.)
  5. additionN sodium hydroxide solution (100 cc.) are added
  6. filtrationAfter filtration
  7. customthe organic phase is recovered
  8. customby decanting
  9. dry with materialis dried over magnesium sulphate
  10. filtrationfiltered
  11. concentrationconcentrated to dryness at 40° C., under reduced pressure (20 mm.Hg)
  12. customThe residue obtained
  13. customis purified by chromatography on silica gel (200 g.)
  14. washdiameter, elution
  15. custombeing collected
  16. concentrationconcentrated to dryness
  17. customThe residue obtained
  18. customis recrystallised from a mixture of isopropanol (70 cc.) and heptane (100 cc.)

Sources & evidence

ORD record
ord-7f4e1c8d5d724e9495011ab5fb6a6374
Source dataset
uspto-grants-1977_12
Patent number
US04064247

Reaction notes

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