Hydrochloric Acid → 2-(1-(Phenylsulfonyl)-1H-indol-5-yl)-4,5-dihydrothiazole-4-carboxylic acid
Reaction equation
[NH:1]1[C:9]2[C:4](=[CH:5][C:6]([C:10]3[S:11][CH2:12][C@@H:13]([C:15]([OH:17])=[O:16])[N:14]=3)=[CH:7][CH:8]=2)[CH:3]=[CH:2]1.[OH-].[Na+].[S:20](Cl)(Cl)(=[O:22])=[O:21].Cl>S([O-])(O)(=O)=O.C([N+](CCCC)(CCCC)CCCC)CCC.C1(C)C=CC=CC=1>[C:4]1([S:20]([N:1]2[C:9]3[C:4](=[CH:5][C:6]([C:10]4[S:11][CH2:12][CH:13]([C:15]([OH:17])=[O:16])[N:14]=4)=[CH:7][CH:8]=3)[CH:3]=[CH:2]2)(=[O:22])=[O:21])[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 2
Procedure
(R)-2-(1H-Indol-5-yl)-4,5-dihydrothiazole-4-carboxylic acid 63a was synthesized from 1H-indole-5-carbonitrile using the same method as used for 42a of U.S. application Ser. No. 12/981,233 (now US2011/0257196) and U.S. application Ser. No. 1/216,927 (now US2012/0071524), incorporated herein by reference in their entirety. Briefly, benzonitrile (40 mmol) was combined with L-cysteine (45 mmol) in 100 mL of 1:1 MeOH/pH 6.4 phosphate buffer solution. The reaction was stirred at 40° C. for 3 days. The precipitate was removed by filtration, and MeOH was removed using rotary evaporation. To the remaining solution was added 1 M HCl to adjust to pH=2 under 0° C. The resulting precipitate was filtered to yield a white solid 2-phenyl-4,5-dihydrothiazole-4-carboxylic acid 42a, which was used directly to next step without purification. To a vigorously stirring solution of 63a (1 mmol) and tetrabutylammonium hydrogen sulfate (0.15 mmol) in toluene (10 mL) at 0° C. was added 50% aqueous sodium hydroxide (10 mL) and sulfonyl chloride (2 mmol). The resultant solution was stirred at RT for 6 h. Then 1 N HCl was added to acidify the mixture to pH=2 and extracted with CH2Cl2, the organic layer was separated and dried (MgSO4); then evaporated to dryness to yield 64a, which were used in subsequent steps without further purification.
Workup
- customwas used directly to next step without purification
- extractionextracted with CH2Cl2
- customthe organic layer was separated
- dry with materialdried (MgSO4)
- customthen evaporated to dryness
Sources & evidence
- ORD record
- ord-ca99a6693fd74effbbbdf5e590a32146
- Source dataset
- uspto-grants-2015_05
- Patent number
- US09029408B2
Reaction notes
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