Round Bottom Flask with three necks

Round Bottom Flask with Three Necks - Your Command Center for Multi-Step Synthesis

I've run countless reactions where I desperately needed that third port, and let me tell you, once you work with a Round Bottom Flask with three necks, you'll wonder how you ever managed with less. These heavy-wall borosilicate beauties are absolute workhorses when you're juggling temperature monitoring, reagent addition, and reflux condensing all at once.

Triple-Port Reaction Vessels for Complex Synthetic Procedures

The three-neck design transforms your reaction setup from basic to professional-grade in seconds. Each neck features precision-ground standard taper joints - typically 14/20, 19/22, 24/29, or 29/32 - that create airtight seals with your condensers, addition funnels, and thermometer adapters. I prefer the 24/29 configuration for most organic synthesis work because it strikes the perfect balance between versatility and stability. Compare this to a Round Bottom Flask with two necks where you're constantly compromising on which accessory to leave out, or even a standard single-neck flask where you're limited to sequential operations rather than simultaneous control.

Multi-Component Reaction Management

• Center neck: Perfect for your reflux condenser or distillation head during workup
• Side ports: Attach a Filter funnel with glass disc for slow reagent addition while monitoring temperature through the opposite port
• Inert atmosphere work: Run nitrogen or argon through one neck while maintaining stirring access through another
• Sampling capability: Extract reaction aliquots without disrupting your setup

When I'm running Grignard reactions or air-sensitive organometallic chemistry, having three access points means I can maintain positive pressure, add reagents dropwise, and monitor temperature without ever breaking my inert seal.

Temperature Monitoring and Reagent Addition Ports

Here's where these flasks really shine: simultaneous operations without compromise. Mount your flask in a heating mantle, insert a thermometer adapter with digital probe in one neck, position your addition funnel in another, and cap the center with a condenser. The vertical sockets configuration keeps everything stable and accessible. For vacuum distillations, I'll often use a Buchner Flask with socket as my receiving vessel while the three-neck flask serves as my distillation pot with pressure equalization, thermometer, and distillation head all connected.

Standard Ground Glass Joint Specifications

Manufactured from Type I borosilicate glass with 3.3 x 10⁻⁶/°C thermal expansion coefficient, these flasks handle thermal shock like champions. Available from 25mL to 5000mL volumes, though I keep 250mL, 500mL, and 1000mL sizes in constant rotation. Pro tip: The uniform wall thickness ensures even heat distribution during reflux, preventing hotspots that can decompose sensitive intermediates. If you need more concentrated volumes for certain extractions, consider a Flask pear shape for your separatory work, but for reactions requiring multiple simultaneous connections, nothing beats the three-neck design.