Sulfuric Acid → 3'-(2,3,5,6-Tetrahydroimidazo[2,1-b]thiazol-6-yl)acetanilide
Reaction equation
Cl.O[CH:3]([C:11]1[CH:12]=[C:13]([CH:18]=[CH:19][CH:20]=1)[NH:14][C:15](=[O:17])[CH3:16])[CH2:4][N:5]1[CH2:9][CH2:8][S:7][C:6]1=[NH:10].S(=O)(=O)(O)O.[OH-].[NH4+]>>[S:7]1[CH2:8][CH2:9][N:5]2[CH2:4][CH:3]([C:11]3[CH:12]=[C:13]([CH:18]=[CH:19][CH:20]=3)[NH:14][C:15](=[O:17])[CH3:16])[N:10]=[C:6]12Participants
Procedure
Addition of 5.00 g. (0.0158 mole) of 3'-[1-hydroxy-2-(2-imino-3-thiazolidinyl)ethyl]acetanilide hydrochloride (Example 6) to 15 ml. of concentrated sulfuric acid is carried out in small increments over 0.5 hour. The orange solution is stirred an additional 1 hour, poured onto ice and made basic with concentrated ammonium hydroxide. The aqueous base is extracted twice with chloroform and the combined organic layers washed with water, brine, dried (sodium sulfate) and evaporated at reduced pressure to give 3.76 g. of an oil. Crystallization from ether gives 3.32 g. (80% crude yield) of fine white crystals, which on recrystallization from 2-propanol gives the product melting point 164°-166° C. Analysis: Calcd. for C13H15N3OS: Calcd: C, 59.74; H, 5.79; N, 16.08; S, 12.27. Found: C, 59.93; H, 5.85; N, 15.96; S, 12.49.
Workup
- additionAddition of 5.00 g
- additionpoured onto ice
- extractionThe aqueous base is extracted twice with chloroform
- washthe combined organic layers washed with water, brine
- dry with materialdried (sodium sulfate)
- customevaporated at reduced pressure
- customto give 3.76 g
- customCrystallization from ether
- customgives 3.32 g
- custom(80% crude yield) of fine white crystals, which on recrystallization from 2-propanol
Sources & evidence
- ORD record
- ord-2584fe792e374fd6b261babaa609145e
- Source dataset
- uspto-grants-1977_03
- Patent number
- US04014892
Reaction notes
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