Acetonitrile → 2-Acetylamino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid ethyl ester

HRID 18681Notes

Reaction equation

HRID 18681 reaction equation
C(#N)C.Br.[CH2:5]([O:7][C:8]([CH:10]1[CH2:19][CH2:18][C:13]2[N:14]=[C:15]([NH2:17])[S:16][C:12]=2[CH2:11]1)=[O:9])[CH3:6].[C:20](OC(=O)C)(=[O:22])[CH3:21]>C(N(CC)CC)C>[CH2:5]([O:7][C:8]([CH:10]1[CH2:19][CH2:18][C:13]2[N:14]=[C:15]([NH:17][C:20](=[O:22])[CH3:21])[S:16][C:12]=2[CH2:11]1)=[O:9])[CH3:6]

Participants

5

Reactant 3

HCID 6342AcetonitrileHCID 7918Acetic AnhydrideHCID 86614358Ethyl 2-amino-4,5,6,7-tetrahydro-1,3-benzothiazole-6-carboxylate hydrobromide

Product 1

HCID 117159592-Acetylamino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid ethyl esterYield 120.1%

Reagents, catalysts & solvents 1

HCID 8471TriethylamineSolvent

Procedure

A 500 ml reactor equipped with mechanical stirrer, thermometer and condenser was loaded with 280 ml of acetonitrile, 71 g of 2-amino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid ethyl ester [(III), R1=ethyl] and 38.75 g of acetic anhydride. 38.03 g of triethylamine were dropwise added to the resulting suspension in about 10 minutes. The suspension was refluxed, obtaining complete dissolution at a temperature ranging from 70 to 75° C. After approx. 2 hours 30 minutes the solution was concentrated to dryness, and the residue was crystallized from 450 ml of isopropanol to obtain 74.5 g of 2-acetylamino-4,5,6,7-tetrahydro-benzothiazole-6-carboxylic acid ethyl ester.

Workup

  1. customA 500 ml reactor equipped with mechanical stirrer
  2. temperatureThe suspension was refluxed
  3. customobtaining complete
  4. dissolutiondissolution at a temperature
  5. customranging from 70 to 75° C
  6. concentrationAfter approx. 2 hours 30 minutes the solution was concentrated to dryness
  7. customthe residue was crystallized from 450 ml of isopropanol

Sources & evidence

ORD record
ord-be78b7c4d6c04f9f8701531c8bc4965e
Source dataset
uspto-grants-2010_06
Patent number
US07741490B2

Reaction notes

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