CINXE.COM
The Merck Index Online - chemicals, drugs and biologicals
<!DOCTYPE html> <html lang="en" class="no-js"> <head> <title>The Merck Index Online - chemicals, drugs and biologicals</title> <meta charset="utf-8"> <meta content="IE=edge" http-equiv="X-UA-Compatible"> <meta content="width=device-width, initial-scale=1.0" name="viewport"> <link rel="canonical" href="https://merckindex.rsc.org" /> <!-- RSC FAVICONS --> <link href="https://www.rsc-cdn.org/oxygen/assets/favicons/favicon.ico" rel="shortcut icon" type="image/x-icon"> <link href="https://www.rsc-cdn.org/oxygen/assets/favicons/apple-touch-icon.png" rel="apple-touch-icon" sizes="180x180"> <link href="https://www.rsc-cdn.org/oxygen/assets/favicons/favicon-32x32.png" rel="icon" sizes="32x32" type="image/png"> <link href="https://www.rsc-cdn.org/oxygen/assets/favicons/favicon-16x16.png" rel="icon" sizes="16x16" type="image/png"> <link href="https://www.rsc-cdn.org/oxygen/assets/favicons/site.webmanifest" rel="manifest"> <link color="#5bbad5" href="https://www.rsc-cdn.org/oxygen/assets/favicons/safari-pinned-tab.svg" rel="mask-icon"> <meta content="#2d89ef" name="msapplication-TileColor"> <meta content="#ffffff" name="theme-color"> <!-- END: RSC FAVICONS --> <link href="https://www.rsc-cdn.org/oxygen/assets/webfonts/fonts.min.css" rel="stylesheet" type="text/css"/> <link href="/dist/a31a9583/css/app.min.css" rel="stylesheet" type="text/css"/> <script>var exports = {};</script> <style> .banner { width: 99%; border-radius: 5px; background-color: #FEE; border: 1px solid #EDD; color: #A66; padding: 25px; margin: auto; font-size: 20px; margin-top: 10px; } .banner-title { font-weight: 700; } @media (max-width: 540px){ .banner { font-size: 14px; } } </style> <!-- Google Tag Manager --> <script type="text/plain" class="optanon-category-C0002"> (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0], j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src= 'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f); })(window,document,'script','dataLayer','GTM-P6LM2ZL'); </script> <!-- End Google Tag Manager --> <!-- Cookies Consent --> <!-- OneTrust Cookies Consent Notice start for merckindex.rsc.org --> <script type="text/javascript" src="https://cdn-ukwest.onetrust.com/consent/0c91d460-5265-4300-a85f-512c3e24ea87/OtAutoBlock.js" ></script> <script src="https://cdn-ukwest.onetrust.com/scripttemplates/otSDKStub.js" type="text/javascript" charset="UTF-8" data-domain-script="0c91d460-5265-4300-a85f-512c3e24ea87" ></script> <script type="text/plain" class="optanon-category-C0001"> function OptanonWrapper() { var onetrustGeolocationResponse = OneTrust.getGeolocationData(); if (onetrustGeolocationResponse.state == "ca") { // If GeoLocation state is CA (Califronia) then show the CA footer link document.getElementById("rsc-onetrust-cookie-footer-global").style.display = "none"; document.getElementById("rsc-onetrust-cookie-footer-ca").style.display = "block"; } else if (onetrustGeolocationResponse.country == "br") { // If GeoLocation country is BR (Brazil) then show the BR footer link document.getElementById("rsc-onetrust-cookie-footer-non-br").style.display = "none"; document.getElementById("rsc-onetrust-cookie-footer-br").style.display = "block"; } } </script> <!-- End Cookies Consent --> </head> <body> <a href="#main" class="skip-to-main-content">Skip to main content</a> <!-- Google Tag Manager (noscript) --> <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-P6LM2ZL" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript> <!-- End Google Tag Manager (noscript) --> <header class="mio-header" id="header" role="banner"> <div class="container"> <div class="rsc-header"> <div class="rsc-header-brand"> <a href="https://www.rsc.org/" aria-label="Royal Society of Chemistry homepage" class="rsc-header-logo"></a> <a href="/" class="rsc-header-title"> <img src="/dist/a31a9583/img/mio-logo.png" alt="The Merck Index Online homepage" class="mio-header-logo" width="350" height="70" /> </a> <a href="#" class="rsc-header-menu-toggle" id="rsc-js-menu-toggle" role="button"> <span id="rsc-js-menu-toggle-open"> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24px" height="24px" fill="black" aria-label="Open menu"> <path d="M0 0h24v24H0V0z" fill="none" /> <path d="M3 18h18v-2H3v2zm0-5h18v-2H3v2zm0-7v2h18V6H3z" /> </svg> </span> <span id="rsc-js-menu-toggle-close" class="hidden"> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24px" height="24px" fill="black" aria-label="Close menu"> <path d="M0 0h24v24H0V0z" fill="none" /> <path d="M19 6.41L17.59 5 12 10.59 6.41 5 5 6.41 10.59 12 5 17.59 6.41 19 12 13.41 17.59 19 19 17.59 13.41 12 19 6.41z" /> </svg> </span> </a> </div> <div class="rsc-header-content"> <a href="/login" class="rsc-header-auth is-loading"> <div id="rsc-js-auth-network" style="display: none;"> <div class="rsc-header-auth-content"> <svg xmlns="http://www.w3.org/2000/svg" class="rsc-header-auth-icon" viewBox="0 0 24 24" width="28px" height="28px" fill="white" aria-hidden="true"> <path d="M0 0h24v24H0z" fill="none"></path> <path d="M12 4c1.93 0 5 1.4 5 5.15 0 2.16-1.72 4.67-5 7.32-3.28-2.65-5-5.17-5-7.32C7 5.4 10.07 4 12 4m0-2C8.73 2 5 4.46 5 9.15c0 3.12 2.33 6.41 7 9.85 4.67-3.44 7-6.73 7-9.85C19 4.46 15.27 2 12 2z"></path> <path d="M12 7c-1.1 0-2 .9-2 2s.9 2 2 2a2 2 0 1 0 0-4zM5 20h14v2H5v-2z"></path> </svg> <div class="rsc-header-auth-login"> <span>Access is provided by:</span> <span style="font-weight:bold;" class="rsc-header-auth-identity"></span> </div> </div> </div> <div id="rsc-js-auth-subscriber" style="display: none;"> <div class="rsc-header-auth-content"> <svg class="rsc-header-auth-icon" width="28px" height="28px" viewBox="0 0 24 24" fill="white" xmlns="http://www.w3.org/2000/svg" aria-hidden="true"> <path d="M12 12C14.21 12 16 10.21 16 8C16 5.79 14.21 4 12 4C9.79 4 8 5.79 8 8C8 10.21 9.79 12 12 12ZM12 14C9.33 14 4 15.34 4 18V20H20V18C20 15.34 14.67 14 12 14Z" fill="#FFFFFF"/> </svg> <div class="rsc-header-auth-login"> <span>Logged in as:</span> <span style="font-weight:bold;" class="rsc-header-auth-identity"></span> </div> </div> </div> <div id="rsc-js-auth-login" style="display: none;"> <div class="rsc-header-auth-content"> <svg xmlns="http://www.w3.org/2000/svg" class="rsc-header-auth-icon" enable-background="new 0 0 24 24" viewBox="0 0 24 24" width="28px" height="28px" fill="white" aria-hidden="true"> <g><rect fill="none" height="24" width="24" /></g> <g><path d="M11,7L9.6,8.4l2.6,2.6H2v2h10.2l-2.6,2.6L11,17l5-5L11,7z M20,19h-8v2h8c1.1,0,2-0.9,2-2V5c0-1.1-0.9-2-2-2h-8v2h8V19z" /></g> </svg> <span class="rsc-header-auth-login">Log in</span> </div> </div> </a> </div> </div> </div> </header> <div class="mio-nav hidden" id="rsc-js-menu"> <nav aria-label="Main" class="container"> <ul class="mio-nav-links"> <li class="active" aria-current="page"> <a id="menu-home" class="mio-nav-link" href="/">Home</a> </li> <li> <a id="menu-browse-monographs" class="mio-nav-link" href="/browse">Browse monographs</a> </li> <li> <a id="menu-advanced-search" class="mio-nav-link" href="/search">Advanced search</a> </li> <li> <a id="menu-reference-tables" class="mio-nav-link" href="/reference">Reference tables</a> </li> </ul> </nav> </div> <div id="banner"></div> <main class="mio-page mio-page-home" id="main" role="main"> <div id="mio-banner" class="mio-banner"> <div class="container"> <div class="columns pt-3"> <div class="column is-7 py-0"> <form method="get" action="/search-results" id="form-search" role="search" aria-label="Sitewide"> <label for="q">Basic search</label> <div class="field mb-2"> <input type="search" name="q" id="q" aria-describedby="qDesc" maxlength="255" required /> <button id="search-btn" aria-label="Search" type="submit"> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="28px" height="28px" fill="white" aria-hidden="true"> <path d="M0 0h24v24H0V0z" fill="none" /> <path d="M15.5 14h-.79l-.28-.27C15.41 12.59 16 11.11 16 9.5 16 5.91 13.09 3 9.5 3S3 5.91 3 9.5 5.91 16 9.5 16c1.61 0 3.09-.59 4.23-1.57l.27.28v.79l5 4.99L20.49 19l-4.99-5zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z" /> </svg> </button> </div> <p class="help" id="qDesc"> Enter a Name, CAS Registry Number or Molecular Formula. </p> </form> </div> <div class="column is-5 py-0 last-updated-container"> <div class="text-container"> <span id="last-updated-label" class="last-updated-label" style="font-size: 1rem;">Last updated:</span> <span id="last-updated-value" class="last-updated-value" style="font-size: 1.2rem; font-weight: bold;"> 12 December 2024 </span> </div> </div> </div> </div> </div> <div class="container"> <div class="mio-page-body"> <div id="merck-index-regarded"> <img src="/dist/a31a9583/img/mio-cover.jpg" alt="" width="250" height="250" /> <h1>The Merck Index* <em>Online</em></h1> <p> For over 130 years The Merck Index has been regarded as the most authoritative and reliable source of key physical, pharmacological and historical information on chemicals, drugs and biologicals. Since 2013, it has been updated by the Royal Society of Chemistry. </p> <p> The Merck Index* <em>Online</em> contains over 12,000 monographs and is continuously expanded with expert-curated content highlighting only the most relevant literature and patents. </p> </div> </div> </div> <div class="container" style="margin-top: 10px;"> <div class="mio-page-body"> <div class="sales"> <div class="sales-info"> <strong>Questions, comments or need to arrange access?</strong><br> <div id="editorial-info">Editorial: <a href="mailto:rscindex@rsc.org">rscindex@rsc.org</a></div> <div id="sales-enquiries-info" >Sales enquiries: <a href="mailto:sales@rsc.org">sales@rsc.org</a></div> </div> <div class="sales-icon"> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon"> <defs> <linearGradient id="header-shape-gradient" x2="0%" y2="100%"> <stop offset="0%" stop-color="#466a75" /> <stop offset="90%" stop-color="#97d700" /> <stop offset="100%" stop-color="#eedc00" /> </linearGradient> </defs> <g> <path fill="url(#header-shape-gradient)" d="M464 64C490.5 64 512 85.49 512 112C512 127.1 504.9 141.3 492.8 150.4L275.2 313.6C263.8 322.1 248.2 322.1 236.8 313.6L19.2 150.4C7.113 141.3 0 127.1 0 112C0 85.49 21.49 64 48 64H464zM217.6 339.2C240.4 356.3 271.6 356.3 294.4 339.2L512 176V384C512 419.3 483.3 448 448 448H64C28.65 448 0 419.3 0 384V176L217.6 339.2z"/> </g> </svg> </div> </div> </div> </div> </main> <div class="disclaimer-banner-container"> <div class="disclaimer-banner"> <div class="container"> <span class="extra">*The name THE MERCK INDEX is owned by Merck & Co., Inc., Rahway, NJ, USA and its affiliates, and is licensed to The Royal Society of Chemistry for use in the USA and Canada.</span> </div> </div> </div> <div class="rsc-ui"> <!-- start oxygen footer --> <footer id="footer" class="rsc-footer"> <div class="breadcrumbs"> <div class="container"> <ul> <li class="extra"> <a id="footer-rsc-org" href="https://www.rsc.org/">rsc.org</a> </li> <li class="extra"> <img src="https://www.rsc-cdn.org/oxygen/assets/icons/chevron-right-light.png" width="8" height="8" alt="" /> <a id="footer-journals-books-databases" href="https://www.rsc.org/journals-books-databases/">Journals, books & databases</a> </li> <li class="extra"> <img src="https://www.rsc-cdn.org/oxygen/assets/icons/chevron-right-light.png" width="8" height="8" alt="" /> <a id="footer-databases-literature-updates" href="https://www.rsc.org/journals-books-databases/databases-literature-updates/">Databases & literature updates</a> </li> <li> <img src="https://www.rsc-cdn.org/oxygen/assets/icons/chevron-right-light.png" width="8" height="8" alt="" /> <a id="footer-mi-go-home" href="/">The Merck Index* <em>Online</em></a> </li> </ul> </div> </div> <div class="nav" id="pnlSiteMap"> <div class="container"> <div class="rsc-logo"> <img id="footer-rsc-logo" src="https://www.rsc-cdn.org/oxygen/assets/logo/rsc-logo-rev.png" alt="Royal Society of Chemistry homepage" width="340" height="85" /> </div> <nav class="links" aria-label="Footer"> <ul> <li><a id="footer-home" href="https://www.rsc.org/">Home</a></li> <li><a id="footer-about" href="https://www.rsc.org/about-us/">About us</a></li> <li><a id="footer-membership" href="https://www.rsc.org/membership-and-community/">Membership & professional community</a></li> <li><a id="footer-campaign" href="https://www.rsc.org/campaigning-outreach/">Campaigning & outreach</a></li> <li><a id="footer-journals" href="https://www.rsc.org/journals-books-databases/">Journals, books & databases</a></li> <li><a id="footer-teaching" href="https://www.rsc.org/teaching-and-learning/">Teaching & learning</a></li> <li><a id="footer-news" href="https://www.rsc.org/news-events/">News & events</a></li> <li><a id="footer-locations" href="https://www.rsc.org/locations-contacts/">Locations & contacts</a></li> <li><a id="footer-careers" href="https://www.rsc.org/careers/">Careers</a></li> <li><a id="footer-awards" href="https://www.rsc.org/awards-funding/">Awards & funding</a></li> <li><a id="footer-advertise" href="https://www.rsc.org/advertise/">Advertise</a></li> <li><a id="footer-help" href="https://www.rsc.org/help-legal/">Help & legal</a></li> <li><a id="footer-privacy" href="https://www.rsc.org/help-legal/legal/privacy/">Privacy policy</a></li> <li><a id="footer-terms" href="https://www.rsc.org/help-legal/legal/terms-conditions/">Terms & conditions</a></li> </ul> </nav> <hr class="clear" /> </div> </div> <div class="baseline"> <div class="container"> <div class="social-icons"> <a id="footer-facebook" href="https://www.facebook.com/RoyalSocietyofChemistry" class="facebook"><img src="https://www.rsc-cdn.org/global/header-footer/images/icons/facebook.png" height="32" width="32" alt="Facebook" /></a> <a id="footer-twitter" href="https://twitter.com/RoySocChem" class="twitter"><img src="https://www.rsc-cdn.org/global/header-footer/images/icons/twitter.png" height="32" width="32" alt="Twitter" /></a> <a id="footer-linkedin" href="https://www.linkedin.com/company/23105" class="linkedin"><img src="https://www.rsc-cdn.org/global/header-footer/images/icons/linkedin.png" height="32" width="32" alt="LinkedIn" /></a> <a id="footer-youtube" href="https://www.youtube.com/user/wwwRSCorg" class="youtube"><img src="https://www.rsc-cdn.org/global/header-footer/images/icons/youtube.png" height="32" width="32" alt="YouTube" /></a> </div> <div id="footer-copyright" class="copyright"> <span id="footer-copyright-pt1">© Royal Society of Chemistry 2025 </span> <br /> <span id="footer-copyright-pt2">Registered charity number: 207890</span> </div> </div> </div> <!-- chemspider-cookies --> <div class="rsc-onetrust-cookie-footer"> <div id="rsc-onetrust-cookie-footer-non-br">This website collects cookies to deliver a better user experience. <span id="rsc-onetrust-cookie-footer-global"> See how this site uses <a href="/cookies">Cookies</a>. </span> <span id="rsc-onetrust-cookie-footer-ca" style="display: none;"> <a href="/cookies">Do not sell my personal data</a>. </span> </div> <div id="rsc-onetrust-cookie-footer-br" style="display: none;"> Este site coleta cookies para oferecer uma melhor experi锟絥cia ao usu锟絩io. <span> Veja como este site usa <a href="/cookies">Cookies</a>. </span> </div> </div> <hr class="clear" /> </footer> <!-- end oxygen footer --> </div> <script src="/dist/a31a9583/js/app.min.js"></script> <script> fetch('/config.json') .then(response => response.json()) .then(res => { let notification = res.notification; if (notification.show){ let todayDate = new Date(); let startDate = new Date(notification.startDate); let endDate = new Date(notification.endDate); const today = new Date(todayDate.toLocaleString('en-US', { timeZone: 'Europe/London' })); const start = new Date(startDate.toLocaleString('en-US', { timeZone: 'Europe/London' })); const end = new Date(endDate.toLocaleString('en-US', { timeZone: 'Europe/London' })); let validDate = notification.show && today >= start && today < end; var contentDiv = document.getElementById("banner"); var bannerDiv = document.createElement("div"); bannerDiv.className = "banner"; var paragraph = document.createElement("p"); var textParagraph = document.createTextNode(notification.message); paragraph.appendChild(textParagraph); if (notification.header != ''){ var spanTitle = document.createElement("span"); spanTitle.className = "banner-title"; var textTitle = document.createTextNode(notification.header); spanTitle.appendChild(textTitle); bannerDiv.appendChild(spanTitle); } if (validDate) contentDiv.appendChild(bannerDiv); bannerDiv.appendChild(paragraph); } }) .catch(error => console.error('Error fetching res:', error)); </script> </body> </html>