Hydrogen Bromide → 2-Bromo-5-methyl-4,5,6,7-tetrahydrothiazolo(5,4-c)pyridine

HRID 1361447Notes

Reaction equation

HRID 1361447 reaction equation
N[C:2]1[S:3][C:4]2[CH2:5][N:6]([CH3:11])[CH2:7][CH2:8][C:9]=2[N:10]=1.[BrH:12].N([O-])=O.[Na+].[OH-].[Na+]>O>[Br:12][C:2]1[S:3][C:4]2[CH2:5][N:6]([CH3:11])[CH2:7][CH2:8][C:9]=2[N:10]=1

Participants

6

Reactant 4

HCID 260Hydrogen BromideHCID 14798Sodium HydroxideHCID 23979985-methyl-4H,5H,6H,7H-[1,3]thiazolo[5,4-c]pyridin-2-amineHCID 23668193Sodium Nitrite

Product 1

HCID 111723352-Bromo-5-methyl-4,5,6,7-tetrahydrothiazolo(5,4-c)pyridine

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
30 °C

Procedure

2-Amino-5-methyl-4,5,6,7-tetrahydrothiazolo[5,4-c]pyridine (600.0 g) was suspended in water (6.0 L), and 48% hydrobromic acid (4.2 L) was added dropwise thereto at 5 to 15° C. A solution of sodium nitrite (367.2 g) in water (1.8 L) was added dropwise thereto at 0 to 5° C. over 1.5 hours, and the reaction mixture was heated to 30° C., followed by stirring for 24 hours. The resultant mixture was made strongly basic (pH 12.5) with 5N aqueous sodium hydroxide (6.0 L). The aqueous layer was extracted with toluene twice (12.0 L, 6.0 L), and the toluene layers were combined. The combined toluene layer was dried over sodium sulfate anhydrate (1202.0 g), and after any insoluble material was filtered off, the mother liquor was concentrated at 40° C. under reduced pressure, to thereby give 557.6 g of the title compound.

Workup

  1. customat 5 to 15° C
  2. extractionThe aqueous layer was extracted with toluene twice (12.0 L, 6.0 L)
  3. dry with materialThe combined toluene layer was dried over sodium sulfate anhydrate (1202.0 g)
  4. filtrationafter any insoluble material was filtered off
  5. concentrationthe mother liquor was concentrated at 40° C. under reduced pressure

Sources & evidence

ORD record
ord-7a108663eefa4d30ac0a21e7929ac0bc
Source dataset
uspto-grants-2011_02
Patent number
US07880005B2

Reaction notes

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