Dimethyl Sulfate → 2-(4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-3-methoxy-2H-indazole
Reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16](=[O:17])[C:15]3[CH2:14][CH2:13][CH2:12][CH2:11][C:10]=3[NH:9]2)=[C:4]([F:18])[CH:3]=1.[OH-].[Na+].S(OC)(O[CH3:25])(=O)=O>O1CCCC1>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16]([O:17][CH3:25])=[C:15]3[C:10]([CH2:11][CH2:12][CH2:13][CH2:14]3)=[N:9]2)=[C:4]([F:18])[CH:3]=1Participants
Procedure
A mixture of 2.1 parts of 2-(4-chloro-2-fluorophenyl)-1,2,4,5,6,7-hexahydro-3H-indazol-3-one, 25 parts of tetrahydrofuran and 5 parts of 10% aqueous sodium hydroxide was reacted with 1.29 parts of dimethyl sulfate. The reaction was stirred at ambient temperature for 20 hours and evaporated at 25° and 100 mm. Hg to yield 2.8 parts of a glass. This glass was chromatographed on 75 parts of Mallinckrodt Silicar CC-7 Special silica gel. The benzene eluent gave a solid which was recrystallized from etherhexane at -70° to yield 0.2 part of 2-(4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-3-methoxy-2H-indazole melting at 100°-102°. The infrared spectrum contained no absorptions for a carbonyl, NH, or OH and the nuclear magnetic reasonance spectrum contained singlet absorption at 4.0 δ characteristic of a methoxy moiety.
Workup
- customevaporated at 25°
- custom100 mm. Hg to yield 2.8 parts of a glass
- customThis glass was chromatographed on 75 parts of Mallinckrodt Silicar CC-7 Special silica gel
- customThe benzene eluent gave a solid which
- customwas recrystallized from etherhexane at -70°
Sources & evidence
- ORD record
- ord-b88acf52452f4bdab194ea2096c5bf6c
- Source dataset
- uspto-grants-1978_10
- Patent number
- US04123252
Reaction notes
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