Imidazole → Ciclopirox

Reaction equation

[CH3:1][C:2]1[CH:7]=[C:6]([CH:8]2[CH2:13][CH2:12][CH2:11][CH2:10][CH2:9]2)[O:5][C:4](=O)[CH:3]=1.S(O)(O)(=O)=O.[NH2:20][OH:21].N1C=CN=C1>>[OH:21][N:20]1[C:6]([CH:8]2[CH2:13][CH2:12][CH2:11][CH2:10][CH2:9]2)=[CH:7][C:2]([CH3:1])=[CH:3][C:4]1=[O:5]

Participants

Reactant 3

HCID 795Imidazole

HCID 159255Hydroxylamine, sulfate (1:1)2×

HCID 198583236-cyclohexyl-4-methyl-2H-pyran-2-one

Product 1

HCID 2749CiclopiroxYield 93.3%

Procedure

20 g of 4-methyl-6-cyclohexyl-2-pyrone, 8 g of hydroxylamine sulfate and 50 g of imidazole were heated to 90° C. Further 10 g of hydroxylamine sulfate were added portionwise in the course of 3 hours. After a reaction time of 5 hours, the mixture was worked up. 11.8 g of 1-hydroxy-4-methyl-6-cyclohexyl-2-pyridone melting at 143° C were obtained.