Pyridine → 67838-56-6

HRID 371651Notes

Reaction equation

HRID 371651 reaction equation
C1(C)C=C[C:4]([S:7](Cl)(=[O:9])=[O:8])=[CH:3][CH:2]=1.[C:12](=[O:15])([O-])[O-].[K+].[K+].[N:18]1C=CC=CC=1>CN(C)C=O.[Pd]>[OH:15][CH2:12][CH:2]1[CH2:3][CH2:4][S:7](=[O:9])(=[O:8])[NH:18]1

Participants

6

Reactant 3

HCID 1049PyridineHCID 73974-Toluenesulfonyl chlorideHCID 11430Potassium Carbonate

Product 1

HCID 2035555967838-56-6

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 6228DimethylformamideSolvent

Procedure

The preparation of intermediate III is seen to involve the following steps: (1) the Grignard reaction of vinylmagnesium bromide with phenoxyacetaldehyde and subsequent acetylation of the complex to yield 4-benzyloxy-3-acetoxy-1-butene; (2) the free radical addition of thiolacetic acid to the double bond of the latter product to yield S-acetyl-3-acetoxy-4-benzyloxy-1-butanethiol; (3) the oxidation of the thiol with chlorine in aqueous acetic acid and reaction of the resulting sulfonyl chloride with ammonia to yield 4-benzyloxy-3-hydroxy-1-butanesulfonamide; (4) tosylation of this compound with p-toluenesulfonyl chloride in pyridine and ring closure with potassium carbonate in dimethylformamide; (5) hydrogenolysis of the protecting benzyl group over a palladium catalyst to yield 3-(hydroxymethyl)isothiazolidine 1,1-dioxide; and (6) alkylation of the latter compound with a lower alkyl ester of 7-bromo-5-heptynoic acid, preferably ethyl 7-bromo-5-heptynoate in dimethylformamide in the presence of potassium carbonate to yield intermediate III.

Sources & evidence

ORD record
ord-0a2a0be45ff4479498cef98a727333e3
Source dataset
uspto-grants-1978_05
Patent number
US04087435

Reaction notes

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