Hydrochloric Acid → HCID 178491637, compound

In the course of 10 min, Ph3P (20.5 g, 78 mmol) in a suspension of the mixture of 3-chlorosulfonyl-4-methoxybenzoic acid and ethyl 3-chlorosulfonyl-4-methoxybenzoate (5.1 g, 19.3 mmol, based on the mass average of ester and acid), obtained under b) is introduced in portions into 50 ml of toluene. After addition is complete, the reaction mixture is stirred at RT for 4.5 h. The fine-crystalline precipitate (Ph3P oxide) is filtered off and washed with toluene. The combined filtrates are extracted 4 times with 30 ml of 10% strength sodium hydroxide solution (120 ml) each time. The aqueous-alkaline extracts are combined, treated with dimethyl sulfate (2 ml/21 mmol), stirred at RT for 2 h and finally heated to boiling temperature. The reaction mixture is cooled to RT and acidified to pH 1 using 20% strength hydrochloric acid with ice-cooling. The white precipitate is filtered off, washed with dist. water and dried. Yield 2.8 g (74%)

1. customobtained under b)
2. additionAfter addition
3. filtrationThe fine-crystalline precipitate (Ph3P oxide) is filtered off
4. washwashed with toluene
5. extractionThe combined filtrates are extracted 4 times with 30 ml of 10% strength sodium hydroxide solution (120 ml) each time
6. stirringstirred at RT for 2 h
7. temperaturefinally heated
8. temperatureThe reaction mixture is cooled to RT
9. temperaturecooling
10. filtrationThe white precipitate is filtered off
11. washwashed with dist
12. dry with materialwater and dried

ORD record

ord-4d0d531203f24cceb44771742858a66a

Source dataset

uspto-grants-2002_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06432988B1