Water → 2-Methyl-4-(6-carbomethoxyhexyl)-thiazole-5-carboxylic acid

HRID 972235Notes

Reaction equation

HRID 972235 reaction equation
[CH3:1][C:2]1[S:3][C:4]([C:16]([OH:18])=[O:17])=[C:5]([CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][C:13]([OH:15])=[O:14])[N:6]=1.O.[C:20]1(C)C=CC(S(O)(=O)=O)=CC=1.O.C(OCC)C>CO.CCCCCC>[CH3:1][C:2]1[S:3][C:4]([C:16]([OH:18])=[O:17])=[C:5]([CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][C:13]([O:15][CH3:20])=[O:14])[N:6]=1

Participants

7

Reactant 4

HCID 962WaterHCID 3283Diethyl EtherHCID 521998p-Toluenesulfonic acid monohydrateHCID 214064232-Methyl-4-(6-carboxyhexyl)-thiazole-5-carboxylic acid

Product 1

HCID 214064072-Methyl-4-(6-carbomethoxyhexyl)-thiazole-5-carboxylic acidYield 79.4%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8058HexaneSolvent

Procedure

5.15 g of 2-methyl-4-(6-carboxyhexyl)-thiazole-5-carboxylic acid (IX, R1 = CH3) and 5.4 g of p-toluenesulphonic acid monohydrate were dissolved in 200 ml of methanol. The reaction mixture was stirred for 2 hours at room temperature, then poured onto 500 ml of water. After saturating the aqueous solution with ammonium sulphate it was extracted with 3 × 200 ml of ethyl acetate, the ethyl acetate extract was washed with water, dried over sodium sulphate and evaporated in vacuo. Recrystallization of the obtained crude product from a mixture of diethyl ether and n-hexane afforded 4.3 g of 2-methyl-4-(6-carbomethoxyhexyl)-thiazole-5-carboxylic acid (X, R1 = CH3). M.p.: 106°-107° C. IR spectrum (KBr): ν OH (carboxylic acid) 3200-2200, ν C=O 1735, 1695, ν C-O 1235 cm-1.

Workup

  1. concentrationAfter saturating the aqueous solution with ammonium sulphate it
  2. extractionwas extracted with 3 × 200 ml of ethyl acetate
  3. extractionthe ethyl acetate extract
  4. washwas washed with water
  5. dry with materialdried over sodium sulphate
  6. customevaporated in vacuo
  7. customRecrystallization of the
  8. customobtained crude product

Sources & evidence

ORD record
ord-30102082f75643a0a407e1bb84ec3495
Source dataset
uspto-grants-1977_10
Patent number
US04052407

Reaction notes

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