4-(3-Hydroxyoctyl)-2,5-dioxo-1,3,4-thiadiazoline-3-heptanoic acid tert-butyl ester → 4-(3-Hydroxyoctyl)-2,5-dioxo-1,3,4-thiadiazoline-3-heptanoic acid
Reaction equation
C([O:5][C:6](=[O:29])[CH:7]=[CH:8][CH2:9][CH2:10][CH2:11][CH2:12][N:13]1[N:17]([CH2:18][CH2:19][CH:20]([OH:26])[CH2:21][CH2:22][CH2:23][CH2:24][CH3:25])[C:16](=[O:27])[S:15][C:14]1=[O:28])(C)(C)C>FC(F)(F)C(O)=O>[OH:26][CH:20]([CH2:21][CH2:22][CH2:23][CH2:24][CH3:25])[CH2:19][CH2:18][N:17]1[C:16](=[O:27])[S:15][C:14](=[O:28])[N:13]1[CH2:12][CH2:11][CH2:10][CH2:9][CH:8]=[CH:7][C:6]([OH:29])=[O:5]Participants
3
Procedure
A solution of 1.95 g (4.5 mmole) of 4-(3-hydroxyoctyl)-2,5-dioxo-1,3,4-thiadiazoline-3-heptanoic acid tert-butyl ester (6) in 10 ml of trifluoroacetic acid was kept at 0° for 1.5 hr and then evaporated at 0° under vacuum. Benzene (75 ml) was added to the residue and the solution re-evaporated. The remaining oil was stirred with 100 ml of 5% NaHCO3 for 1 hr and extracted with ether, the ether extract then being discarded. The remaining aqueous raffinate was then acidified with HCl and extracted with ether, giving 1.7 g of 4-(3-hydroxyoctyl)-2,5-dioxo-1,3,4-thiadiazoline-3-heptanoic acid (8); Rf =0.26 on silica gel, 1:1 CHCl3 --ether, I2 visualization. Acid 8 was identified by its solubility in 5% NaHCO3.
Workup
- customevaporated at 0° under vacuum
- additionBenzene (75 ml) was added to the residue
- customthe solution re-evaporated
- extractionextracted with ether
- extractionthe ether extract
- extractionextracted with ether
Sources & evidence
- ORD record
- ord-0f9cf76608eb4f8fa9553769b24a3274
- Source dataset
- uspto-grants-1977_06
- Patent number
- US04032533
Reaction notes
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