Vogel's 5th Edition Alkyl Nitrites

Topic created by Nitritespecialist
on Thu, 4 Mar 2021 at 21:40

Nitritespecialist said on Thu, 4 Mar 2021 at 21:40...

These are readily prepared by interaction at 0C of the alcohol with sodium nitrite in the presence of excess of concentrated sulphuric acid.

For pentyl nitrite, equip a 1-litre three necked flask with a powerful mechanical stirrer, a separatory funnel with stem extending to the bottom of flask and a thermometer. Cool flask in a mixture of ice and salt. Place a solution of 95g sodium nitrite in 375 ml of water in the flask and stir. When temperature has fallen to 0C or slightly lower, introduce slowly from the separatory funnel a mixture of 25 ml of water, 6.25g(34ml) of concentrated sulphuric and 110g(135ml) of pentan-1-ol, which has previously been cooled to 0C. The rate of addition must be controlled so that the temperature is maintained at + or minus 1C. Allow mixture to stand for 1.5 hours and then filter from the precipitated sodium sulphate. Separate the upper yellow pentyl nitrite layer, wash with a solution containing 1 gram of sodium hydrogen carbonate(baking soda) and 12.5 grams of sodium chloride in 50 ml water. Dry with 5-7 grams magnesium sulphate. Resulting crude pentyl nitrite (107grams or 73%), is good enough for many purposes. Upon distillation, it passes over at 104C with little decomposition.

Nitritespecialist said on Fri, 5 Mar 2021 at 19:58...

I read a patent that says this synthesis works better if the reaction is seeded with about 1% sodium sulfate decahydrate which is a special form that has water in it. This is added after about 10% of the sulfuric acid is added. The patent states it helps the normal sodium sulfate precipitate coming from the reaction to precipitate out of the solution instead of building up to a sudden exothermic release. It can be purchased on Amazon.

This patent also uses 4% by weight Epoxidized vegetable oil to act as a stabilizer/acid scavenger. This oil, linseed or soybean for example, is a specially treated oil that is made by adding concentrated hydrogen peroxide to acetic acid and then adding to the oil and then an acid catalyst is added. Reaction is exothermic and needs steady control.

I wonder if PWD used this as a preservative. Amyl nitrite ampules having been using it for awhile.