Sulfuric Acid → t-Butyl 2-(6-amino-3-bromo-5-hydroxy-2-pyridylazo)-5-(3-hydroxybenzoyl)-4-methyl-3-thenoate

HRID 434333Notes

Reaction equation

HRID 434333 reaction equation
[NH2:1][C:2]1[S:6][C:5]([C:7](=[O:15])[C:8]2[CH:13]=[CH:12][CH:11]=[C:10]([OH:14])[CH:9]=2)=[C:4]([CH3:16])[C:3]=1[C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18].S(=O)(=O)(O)O.[N:29]([O-])=O.[Na+].[NH2:33][C:34]1[C:39]([OH:40])=[CH:38][C:37]([Br:41])=[CH:36][N:35]=1>O.N1C=CC=CC=1>[NH2:33][C:34]1[N:35]=[C:36]([N:29]=[N:1][C:2]2[S:6][C:5]([C:7](=[O:15])[C:8]3[CH:13]=[CH:12][CH:11]=[C:10]([OH:14])[CH:9]=3)=[C:4]([CH3:16])[C:3]=2[C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])[C:37]([Br:41])=[CH:38][C:39]=1[OH:40]

Participants

7

Reactant 4

HCID 1118Sulfuric AcidHCID 116940412-Amino-5-bromo-3-hydroxypyridineHCID 20493219t-Butyl 2-amino-5-(3-hydroxybenzoyl)-4-methyl-3-thenoateHCID 23668193Sodium Nitrite

Product 1

HCID 136103497t-Butyl 2-(6-amino-3-bromo-5-hydroxy-2-pyridylazo)-5-(3-hydroxybenzoyl)-4-methyl-3-thenoateYield 72%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 1049PyridineSolvent

Procedure

A slurry of t-butyl 2-amino-5-(3-hydroxybenzoyl)-4-methyl-3-thenoate in 150 ml of 1:5 acid (see Example 1-C) was cooled to 0° to 5° C. and 9 ml of concentrated sulfuric acid was added below 5° C. A solution of 4.21 g (0.61 mole) of sodium nitrite in 10 ml of water was slowly added, holding the temperature at 0° to 5° C. during the addition. The diazonium was stirred for 1.5 hours at 0° to 5° C. and then was added below 10° C. to a solution of 11.34 g of 2-amino-5-bromo-3-pyridinol (Example 2-L) dissolved in 30 ml of pyridine and 25 ml of 2:5 acid. The mixture was stirred for 2 hours at 0° to 5° C., then poured into cold water. The resulting mixture was filtered, washed with water, air dried and recrystallized from ethyl cellosolve to give 23 g (72 percent) of a red solid, used without further purification.

Workup

  1. customat 0° to 5° C.
  2. additionduring the addition
  3. filtrationThe resulting mixture was filtered
  4. washwashed with water, air
  5. customdried
  6. customrecrystallized from ethyl cellosolve

Sources & evidence

ORD record
ord-a6d50873454f4a988cbcf9e6d129ba32
Source dataset
uspto-grants-1983_08
Patent number
US04396546

Reaction notes

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