Iodoethane → Ethyl-7-methoxy-1-oxo-1H-pyrimido[6,1-b]benzthiazole-4-carboxylate

HRID 224350Notes

Reaction equation

HRID 224350 reaction equation
[Na].[CH3:2][O:3][C:4]1[CH:20]=[CH:19][C:7]2[N:8]3[C:14](=[O:15])[N:13]=[CH:12][C:11]([C:16]([OH:18])=[O:17])=[C:9]3[S:10][C:6]=2[CH:5]=1.O=P(N(C)C)(N(C)C)N(C)C.[CH2:32](I)[CH3:33]>O>[CH2:32]([O:17][C:16]([C:11]1[CH:12]=[N:13][C:14](=[O:15])[N:8]2[C:7]3[CH:19]=[CH:20][C:4]([O:3][CH3:2])=[CH:5][C:6]=3[S:10][C:9]=12)=[O:18])[CH3:33]

Participants

6

Reactant 4

HCID 6340IodoethaneHCID 12679HexamethylphosphoramideHCID 5360545SodiumHCID 233327897-Methoxy-1-oxo-1H-pyrimido[6,1-b]benzthiazole-4-carboxylic acid

Product 1

HCID 23332809Ethyl-7-methoxy-1-oxo-1H-pyrimido[6,1-b]benzthiazole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

20 g. of the sodium salt of 7-methoxy-1-oxo-1H-pyrimido[6,1-b]benzthiazole-4-carboxylic acid prepared according to Example 1C are slurried in 200 ml. hexametapol and mixed at ambient temperature with 23.45 g. ethyl iodide. The reaction mixture is stirred for 80 minutes and the resultant solution poured into 3 liters of water. The precipitate obtained is separated off and, while still moist, boiled with 500 ml. ethanol and brought into solution by the addition of some nitromethane. After cooling, 12.9 g. (63.3% of theory) ethyl 7-methoxy-1-oxo-1H-pyrimido[6,1-b]benzthiazole-4-carboxylate crystallize out; m.p. 231°-232° C.

Workup

  1. customThe precipitate obtained
  2. customis separated off
  3. additionethanol and brought into solution by the addition of some nitromethane
  4. temperatureAfter cooling
  5. custom(63.3% of theory) ethyl 7-methoxy-1-oxo-1H-pyrimido[6,1-b]benzthiazole-4-carboxylate crystallize out

Sources & evidence

ORD record
ord-3820fdd409ce450eaa003f1788cb2acb
Source dataset
uspto-grants-1980_11
Patent number
US04232024

Reaction notes

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