Isopropanol → alpha-Amino-9H-thioxanthene-9-acetic acid, hydrochloride

HRID 258193Notes

Reaction equation

HRID 258193 reaction equation
[ClH:1].[NH2:2][CH:3]([CH:9]1[C:22]2[CH:21]=[CH:20][CH:19]=[CH:18][C:17]=2[S:16][C:15]2[C:10]1=[CH:11][CH:12]=[CH:13][CH:14]=2)[C:4]([O:6]CC)=[O:5].[OH-].[K+].CCCCCC.CC(O)C>C(O)C.O>[ClH:1].[NH2:2][CH:3]([CH:9]1[C:10]2[CH:11]=[CH:12][CH:13]=[CH:14][C:15]=2[S:16][C:17]2[C:22]1=[CH:21][CH:20]=[CH:19][CH:18]=2)[C:4]([OH:6])=[O:5]

Participants

7

Reactant 4

HCID 3776IsopropanolHCID 8058HexaneHCID 14797Potassium HydroxideHCID 67804420Ethyl alpha-amino-9H-thioxanthene-9-acetate hydrochloride

Product 1

HCID 67803772alpha-Amino-9H-thioxanthene-9-acetic acid, hydrochlorideYield 18.5%

Reagents, catalysts & solvents 2

HCID 702EthanolSolvent2×HCID 962WaterSolvent

Procedure

Ethyl α-amino-9H-thioxanthene-9-acetate hydrochloride (3.5 g, 10 mmol) is dissolved in 30 mL of absolute ethanol and 33 mL of 1.25 M ethanolic potassium hydroxide solution (4 equivalents) is added. The reaction mixture is stirred at room temperature for 22 hours when TLC (SiO2, hexane:2-propanol/3:1) shows no starting material. Ethanol is stripped under vacuum and the residue taken up in 75 mL of water and extracted with diethyl ether. The aqueous solution is acidified with 1N hydrochloric acid to pH 7 and a precipitate is collected by filtration, washed with water, dried at 45° C./2 mm Hg over phosphorous pentoxide (P2O5). This gives 1.65 g of the title compound; mp 244°-246° C. The mother liquor is concentrated, cooled at +3° C. to furnish the second crop (0.57 g) of the title compound as a hydrochloride free base mixture. The above solids are combined in 50 mL of water and treated with 1N hydrochloric acid to pH 1. The mixture is stripped to dryness under vacuum and the residue dried at 50° C./2 mm Hg to give the title compound; mp 269°-273° C. (dec).

Workup

  1. extractionextracted with diethyl ether
  2. filtrationa precipitate is collected by filtration
  3. washwashed with water
  4. dry with materialdried at 45° C./2 mm Hg over phosphorous pentoxide (P2O5)
  5. concentrationThe mother liquor is concentrated
  6. temperaturecooled at +3° C.

Sources & evidence

ORD record
ord-c05e363cd3b74c1ebf123f047a03c022
Source dataset
uspto-grants-1993_11
Patent number
US05264577

Reaction notes

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