Methyl chloroformate → HCID 54063869, compound

HRID 1600698Notes

Reaction equation

[Cl:1][C:2]1[C:3]([OH:25])=[C:4]([C:16]2[C:21]([CH3:22])=[CH:20][C:19]([CH3:23])=[CH:18][C:17]=2[CH3:24])[C:5](=[O:15])[O:6][C:7]=1[C:8]1[CH:13]=[CH:12][C:11]([Cl:14])=[CH:10][CH:9]=1.C(N(CC)CC)C.Cl[C:34]([O:36][CH3:37])=[O:35]>C(OCC)(=O)C>[Cl:1][C:2]1[C:3]([O:25][C:34]([O:36][CH3:37])=[O:35])=[C:4]([C:16]2[C:21]([CH3:22])=[CH:20][C:19]([CH3:23])=[CH:18][C:17]=2[CH3:24])[C:5](=[O:15])[O:6][C:7]=1[C:8]1[CH:9]=[CH:10][C:11]([Cl:14])=[CH:12][CH:13]=1

Participants

Conditions

Temperature: 20 °C

Procedure

3.8 g (10 mmol) of 5-chloro-6-(4-chlorophenyl)-4-hydroxy-3-(2,4,6-trimethylphenyl)-2-pyrone (Example I-a-1) are initially charged in 25 ml of ethyl acetate. At 20° C., 1.0 g (10 mmol) of triethylamine are added and a solution of 0.95 g (10 mmol) of methyl chloroformate in 10 ml of ethyl acetate is added dropwise at 0° C. The mixture is subsequently stirred at 20° C. for 20 h. Precipitated triethylamine hydrochloride is filtered off with suction and washed with ethyl acetate. The combined mother liquors are washed twice with 50 ml of half-concentrated sodium chloride solution each time, dried over magnesium sulphate and concentrated under reduced pressure. 4.0 g (92.4% of theory) of crude 5-chloro-6-(4-chlorophenyl)-4-methoxycarbonyloxy-(2,4,6-trimethylphenyl)-2-pyrone are obtained. Recrystallization from 50 ml of cyclohexane affords 3.1 g (72% of theory) of pure product which melts at 136-138° C.

Workup

filtrationPrecipitated triethylamine hydrochloride is filtered off with suction
washwashed with ethyl acetate
washThe combined mother liquors are washed twice with 50 ml of half-concentrated sodium chloride solution each time
dry with materialdried over magnesium sulphate
concentrationconcentrated under reduced pressure

Sources & evidence

ORD record: ord-8f54f375e02a4a35b9693ec22758b5a0
Source dataset: uspto-grants-1999_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05977029

Reaction notes

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