Ethchlorvynol
;)
1-Penten-4-yn-3-ol,1-chloro-3-ethyl-.
1-Chloro-3-ethyl-1-penten-4-yn-3-ol [113-18-8].
»Ethchlorvynol contains not less than 98.0percent and not more than 100.0percent of E-ethchlorvynol (C7H9ClO),calculated on the anhydrous basis.
Packaging and storage—
Preserve in tight,light-resistant glass or polyethylene containers,using polyethylene-lined closures.
Identification—
A:
Infrared Absorption á197Fñ.
B:
Dissolve about 1g in 20mLof methanol.To 1mLof the solution,add about 4drops of 6Nammonium hydroxide,mix,then add silver nitrate TS,a few drops at a time:a yellowish white precipitate is formed,and it at first redissolves,but becomes insoluble when an excess of silver nitrate TShas been added.
C:
To 10mLof the solution prepared in Identificationtest Badd 5mLof freshly prepared m-phenylenediamine hydrochloride-oxalic acid solution (prepared by dissolving 1g of m-phenylenediamine hydrochloride and 1g of oxalic acid in 35mLof water and filtering,if necessary):a reddish orange color is produced in about 3minutes.
Refractive index á831ñ:
between 1.476and 1.480.
Acidity—
Dissolve 5.0mLof Ethchlorvynol in 50mLof a mixture of equal volumes of water and methanol that has been neutralized to the phenolphthalein endpoint with 0.1Nsodium hydroxide.Add 1mLof phenolphthalein TS,and titrate with 0.10Nsodium hydroxide to a pink endpoint:not more than 1.7mLof 0.10Nsodium hydroxide is required for neutralization.
Water,Method Iá921ñ:
not more than 0.2%.
Chromatographic purity—
Calculate the percentage of each peak,other than the E-ethchlorvynol peak,observed in the chromatogram of the Ethchlorvynol obtained as directed in the Assaytaken by the same formula:
100ri/rt,
in which riis the response of each secondary peak and rtis the sum of all of the peaks observed in the chromatogram:not more than 0.2%of toluene,not more than 1.5%of Z-ethchlorvynol,and not more than 0.3%of any other impurity is found,and the total of all observed impurities is not more than 2.0%.
Assay—
Resolution solution—
Add 2.5µLof toluene to 0.5mLof USP Ethchlorvynol RS,and mix.
Chromatographic system
(see Chromatography á621ñ)—The gas chromatograph is equipped with a thermal conductivity detector and a 1.8-m ×4-mm glass column (pretreated with 10%dimethyldichlorosilane in toluene)packed with 10%phase G16on 60-to 80-mesh support S1AB.The column is maintained at about 160
,and the injector and the detector are maintained at about 200.The carrier gas is dry helium,flowing at a rate of about 30mLper minute.Chromatograph the Resolution solution,and record the peak responses as directed for Procedure:the relative retention times for toluene,b-chlorovinylethyl ketone (if present),Z-ethchlorvynol,and E-ethchlorvynol are about 0.1,0.2,0.8,and 1.0,respectively;the resolution,R,between the Z-and E-ethchlorvynol peaks is not less than 1.0;and the relative standard deviation for replicate injections is not more than 2.0%.
,and the injector and the detector are maintained at about 200.The carrier gas is dry helium,flowing at a rate of about 30mLper minute.Chromatograph the Resolution solution,and record the peak responses as directed for Procedure:the relative retention times for toluene,b-chlorovinylethyl ketone (if present),Z-ethchlorvynol,and E-ethchlorvynol are about 0.1,0.2,0.8,and 1.0,respectively;the resolution,R,between the Z-and E-ethchlorvynol peaks is not less than 1.0;and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure—
[NOTE—Use peak areas where peak responses are indicated.]Inject about 3µLof Ethchlorvynol into the chromatograph,record the chromatogram,and measure the responses for all of the peaks.Calculate the percentage of E-ethchlorvynol (C7H9ClO)in the specimen of Ethchlorvynol taken by the formula:
100re/rt,
in which reis the response of the E-ethchlorvynol peak obtained in the chromatogram of the Ethchlorvynol and rtis the sum of the responses of all of the peaks observed in the chromatogram.
Auxiliary Information—
Staff Liaison:Salvador C.Salado,M.S.,Scientist and Latin American Liaison
Expert Committee:(PA3)Pharmaceutical Analysis 3
USP28–NF23Page 787
Phone Number:1-301-816-8165