Hypophosphoric acid → Methyl 4-Methylbenzothiazole-5-carboxylate

HRID 1263403Notes

Reaction equation

HRID 1263403 reaction equation
N[C:2]1[S:3][C:4]2[CH:10]=[CH:9][C:8]([C:11]([O:13][CH3:14])=[O:12])=[C:7]([CH3:15])[C:5]=2[N:6]=1.N([O-])=O.[Na+].P(P(O)(O)=O)(O)(O)=O>P(=O)(O)(O)O.O>[CH3:15][C:7]1[C:5]2[N:6]=[CH:2][S:3][C:4]=2[CH:10]=[CH:9][C:8]=1[C:11]([O:13][CH3:14])=[O:12]

Participants

6

Reactant 3

HCID 24536Hypophosphoric acidHCID 22390084Methyl 2-amino-4-methylbenzo[d]thiazole-5-carboxylateHCID 23668193Sodium Nitrite

Product 1

HCID 18616057Methyl 4-Methylbenzothiazole-5-carboxylate

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1004Phosphoric AcidSolvent

Conditions

Temperature
-8 °C

Procedure

15 g of methyl 2-amino-4-methylbenzothiazole-5-carboxylate (0.07 mol) were initially charged in 450 ml of phosphoric acid, and the mixture was cooled to −8° C. 27.9 g of NaNO2 (0.4 mol) in 30 ml of water were then added dropwise such that the temperature did not exceed −4° C. The diazonium salt was then added dropwise, at 5-10° C., to 169 ml of hypophosphoric acid, and the mixture was stirred at 20° C. overnight. The reaction solution was then neutralized and extracted exhaustively with ethyl acetate. The organic phases Age were washed and dried and the solvent was then removed.

Workup

  1. customdid not exceed −4° C
  2. extractionextracted exhaustively with ethyl acetate
  3. washThe organic phases Age were washed
  4. customdried
  5. customthe solvent was then removed

Sources & evidence

ORD record
ord-936b0fc5f8544d52824550e09c5cce83
Source dataset
uspto-grants-2003_04
Patent number
US06541423B1

Reaction notes

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