Reaction equation
[CH3:1][N:2]1[C:10]2[CH2:9][CH2:8][CH2:7][C:6](=[O:11])[C:5]=2[CH:4]=[N:3]1.[H-].[Na+].[CH:14](OCC)=[O:15]>C(O)C.C1(C)C=CC=CC=1>[OH:15][CH:14]=[C:7]1[CH2:8][CH2:9][C:10]2[N:2]([CH3:1])[N:3]=[CH:4][C:5]=2[C:6]1=[O:11]Participants
Procedure
A stirred mixture 16.8 grams of 1,5,6,7-tetrahydro-1-methyl-4H-indazol-4-one, 6 grams of 97% sodium hydride, 15 ml of ethyl formate, 3 drops of ethanol and 200 ml of toluene was heated at reflux for 16 hours. The mixture was then cooled and extracted twice with water and the aqueous extracts were combined and washed with ethyl ether. The aqueous solution was acidified with 5 N hydrochloric acid to a pH of approximately 4 and the resultant slurry was extracted several times with dichloromethane. The combined dichloromethane extracts were dried over magnesium sulfate and concentrated under reduced pressure to leave a residual dark oil. The oil was triturated with a 50:50 mixture of hexane and ethyl ether to give 1,5,6,7-tetrahydro-5-hydroxymethylene-1-methyl-4H-indazol-4-one melting at about 93°-95° C.
Workup
- temperatureat reflux for 16 hours
- temperatureThe mixture was then cooled
- extractionextracted twice with water
- washwashed with ethyl ether
- extractionthe resultant slurry was extracted several times with dichloromethane
- dry with materialThe combined dichloromethane extracts were dried over magnesium sulfate
- concentrationconcentrated under reduced pressure
- customto leave a residual dark oil
- customThe oil was triturated with a 50:50 mixture of hexane and ethyl ether
Sources & evidence
- ORD record
- ord-7c61805d19484f8f8d96b5d159bb9db1
- Source dataset
- uspto-grants-1988_03
- Patent number
- US04734430
Linked notes
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