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Diazomethane Distillation Apparatus

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Diazomethane • Kugelrohr Miscellaneous

Diazomethane Distillation Apparatus

On this page:
Mini Diazald apparatusMacro Diazald kitsEther trap • Diazald glassware setDiazomethane precursorsMNNG diazomethane-generator

For further information Please refer to Technical Information Bulletin No. AL-180 and for a review on the preparation and reactions of diazomethane, see Aldrichim. Acta 1983, 16 (1), 3.

Mini Diazald apparatus

The mini Diazald apparatus bridges the gap between the MNNG diazomethane generator (for preparing <1mmol of diazomethane) and the Diazald kit (for preparing ~100mmol of diazomethane). It consists of a reaction vessel and a condenser in one compact unit.

This apparatus features a cold-finger in place of a water-jacketed condenser. When filled with dry ice/acetone slush, the condenser efficiently prevents dangerous diazomethane/ether vapor from escaping. A separatory funnel, Z10,038-2 and a round-bottom receiving flask, Z10,035-8, (must be equipped with Clear-Seal joints) are the only other glassware needed and can be purchased separately.

With S.T. 19/22 Clear-Seal joints
With S.T. 19/26 Clear-Seal joints
Separatory funnel, 125mL
Round-Bottom flask, 100mL

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Macro Diazald kits

Designed by M. Hudlicky (J. Org. Chem. 1980, 45, 5377). The stopcock is closed at the start of distillation. As the distillate drips off the condenser, the stopcock is opened and the first portions fill the trap, allowing diazomethane/ether condensate to collect in the 500mL Erlenmeyer flask, but prevents the escape of uncondensed vapors into the receiver. Glassware has Clear-Seal joints, which do not require grease and are safer because of their smooth surfaces (sharp edges and ground glass must be avoided in diazomethane generation). Thermometer not included.

With S.T. 24/40 Clear-Seal joints
With S.T. 29/32 Clear-Seal joints
Replacement parts


S.T. 24/40 Joints
Catalog Number
S.T. 29/32 Joints
Catalog Number
PTFE stopper
Dropping funnel, 500mL
Round-bottom flask, 2-neck, 500mL
Cold-finger condenser assembly
Erlenmeyer flask, 500mL
Erlenmeyer flask, 1,000mL (optional)

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Ether trap

4mL capacity, 75mm length. Glass is inspected for scratches and ends are fire-polished. Traps diazomethane/ether vapors.

Catalog Number
Inlet, straight
Inlet, 90° bend

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Diazald glassware set with System 45 compatible connections

This newly designed glassware set incorporates System 45 compatible connections that eliminate glass joints, clamps, and grease and permits the safe preparation of diazomethane (~100mmol) from Diazald. The unique, one-piece distillation head features a highly efficient coiled condenser.

Note: order ether trap separately below.

Catalog Number
Glassware set, complete

Replacement parts
Addition funnel, 60mL, with PTFE valve
Distillation head
PTFE inlet adapter, for 8mm tubing
PTFE inlet adapter, for 13mm tubing
PTFE vacuum adapter, for 10mm tubing
Round-bottom flask, 100mL
Solid-top cap, with PTFE liner, 25mm
Solid-top cap, with PTFE liner, 32mm
Quick-disconnect fittings, w/ 1/4in. hose fitting
O-rings, Viton, size 2-011, for use with quick-disconnect fittings, Z41,743-2
Ether trap

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Diazomethane precusors and related products

Catalog Number
Diazald, 99%
Diazald-N-methyl-13C, 99 atom % 13C
Diazald-N-methyl-13C-N-methyl-d3, 99 atom % D
Diazald-N-methyl-d3, 98 atom % D
1-Methyl-3-nitro-1-nitrosoguanidine, 97%

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MNNG diazomethane-generator
with System 45 compatible connection

MNNG (1-methyl-3-nitro-1-nitrosoguanidine, 12,994-1) is probably the most convenient precursor to diazomethane because it is stable and crystalline, and generates diazomethane upon treatment with aqueous alkali.

This newly designed apparatus incorporates System 45 compatible technology that eliminates glass joints, clamps, and grease and permits the preparation of diazomethane without the need for codistillation with ether (see below) Request Technical Information Bulletin No. AL-180.

The screw thread closure and PTFE adapter provide an efficient, gas tight connection between the inner tube and the outer body section. For storage, simply remove the inner tube assembly from the threaded outer section and screw on the PTFE lined screw cap. Access to the material may be made through the open top septum cap with a syringe. Supplied complete with threaded body, threaded inner tube, PTFE adapter, 32mm cap, O-ring, lock nut, septum and 8mm open top cap.

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Typical Generator Setup:

  • 1mmol (133mg) or less of MNNG reagent is placed in the inside tube through the 8mm open top screw cap along with 0.5mL of water to dissipate any heat generated
  • Ether (~3mL) is placed in the outside tube and the two parts are assembled and held together by tightening the 32mm screw cap
  • Immersethe lower part in an ice bath and inject (dropwise, very slowly to prevent froth ing or possible buildup of back pressure) about 0.6mL of 5N sodium hydroxide through the PTFE-faced silicone septum via a syringe with a narrow gauge (No.22) needle to prevent diazomethane leakage around the shank. (See below for syringe ordering information)
  • Diazomethane collects in the ether ready for use

Diazoethane, despite its lower volatility, can be generated similarly from ENNG (1-ethyl-3-nitro-1-nitrosoguanidine, E4,160-5). This apparatus is also useful for the generation of radioactive or deuterated diazomethane because it is a closed system.

WARNING: MNNG is mutagenic and exposure may cause skin sensitivity. While MNNG is more convenient for the generation of small quantities of diazomethane, Diazald is the preferred reagent for large-scale production of diazomethane. However, it has recently been reported that Diazald can be used in place of MNNG in the above apparatus. (See: F. Ngan and M. Toofan, Journal of Chromatographic Science, 1991, 29, 8.) Diazomethane has been reported to be explosive, particularly on contact with ground-glass joints during distillation.

Catalog Number
MMNG diazomethane generator

Replacement parts
O-ring seal
PTFE-faced silicone septum, 32mm
PTFE-faced silicone septum, 8mm
Screw cap with hole, 8mm
Disposable syringes: All PE/PP, 1mL
Disposable needles: 22 gauge, 1in. L

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