Preparation of Diazomethane

From: http://www.tcieurope.eu/en/product/synthetic-chem/S026.shtml

A reaction and distillation apparatus is assembled by connecting an addition funnel and condensor to a 100ml long-neck distillation flask. Two in series receiving flasks are connected to the apparatus with the second flask containing an induction tube. A solution containing 6g potassium hydroxide in 10ml water, and a solution containing 35ml Carbitol (Diethylene glycol monoethyl ether) and 10ml of ether are placed in the distillation flask. 20 ~ 30ml ether is placed in the second receiving flask making sure the induction tube is immersed into the ether. Both receiving flasks are cooled to 0ºC. A solution containing p-toluenesulfonyl-N- methyl-N-nitrosamide (21.5g, 0.1mol) in 140ml ether is placed in the addition funnel. Heat the distillation flask to 70ºC in a warm water bath. As the ether begins to boil, start adding the p-toluenesulfonyl-N-methyl-N-nitrosamide solution dropwise over a 20 minute period. Swirl distillation flask from time to time. About 3g of diazomethane (0.07mol) is dissolved in ether distillate.
　The reagent should be used at once without storing it.
* Diazomethane is explosive and highly toxic. Wear protective gloves, protective goggles, protective mask and work in a well ventilated fume hood. Also place a safety shield in front of distillation apparatus. Diazomethane may explode upon contact with ground glass joints or other scratched glass surfaces, so avoid handling or preparing this compound with such surfaces. Ordinarily, diazomethane is used as a solution in ether.
*We have TMS diazomethane available. This reagent is analogous in reactivity to diazomethane, but less explosive and less toxic. Please consider using this reagent prior to preparing diazomethane.
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Note:
0. diazomethane is yellow colored, easy to know when to stop ether distillation.
1. the diazomethane distilled by this way contains water, if anhydrous diazomethane needed, KOH pellets can be added into the diazomethane ether solution and put in freezer overnit to get dry diazomethane.
2. TMS diazomethane can't replace diazomethane, although in most case, it is a good substitutuion.
3. dry diazomethane ether solution can be stored in freezer for a while (several days). when diazomethane decomposed, the yellow color will disappear.