Hello AFOAF looked into the peacefull pill book and in the synthesis of this compound (Nembutal, sodic pentobarbitone) synthesis, and in the step 2 and three they say you need also sodium ethoxide as a catalyst, but I don't know how much, this is the only thing that AFOAF don't know about the recipe and he had synthesized organic compounds in the past because he is an amature chemist but don't know how much sodium ethoxide is needed for step 2 and step 3.
And also in the book sodium ethoxide is prepared in situ in the reaction vessel for the step 1 reaction, but he have access to 20% sodium ethoxide solution in absolutely dry ethanol or simply sodium ethoxide, so he can pass through the step of making it in situ.
So if anyone can tell how much sodium ethoxide is produced also in step 1 to directly add the already made sodium ethoxide will be very appreciated.
This is the ''Peacefull Pill Project'' part of the book where the synthesis is written:
''
Step 1
In the case of the target barbiturates, Nembutal or Amytal, the first sidechain to be attached to the di-ethyl malonate is an ethyl halide, usually ethyl bromide is used. To form the mono-sustituted malonic ester, ethyl bromide is heated with the di-ethyl malonate in the presence of the required catalyst - the base, sodium ethoxide.
The catalyst may be purchased or made as part of the process. To make the required ethoxide add 5.7g of metallic sodium that has been cleaned by passing through a press - see 'Betty cooks with Sodium' - and 125m1 of very dry alcohol.
Into this mixture of dry alcohol and sodium ethoxide add 38m1 of di-ethyl malonate and 26g of bromoethane. Heat is applied and the mixture stirred using a magnetic stirrer. In an open system a reflux condenser must be fitted and a calcium chloride guard tube used to ensure no contamination by atmospheric moisture.
Note: Super Dry Alcohol
Alcohol (ethanol) of the required dryness can be made using methylated spirits as the starting point (95.6% alcohol). Absolute ethanol (>99.5%) is obtained by heating this under reflux with dry (recently fired) calcium oxide. To significantly improve the yield in the synthesis of barbiturates, even dryer alcohol is required. To remove more of the water, thereby converting the 99.5% ethanol to 'super dry' alcohol (>99.8%), use 5gm of magnesium turnings with 0.5gm of iodine in a boiling vessel. Let the magnesium react with —50m1 of the 99.5% ethanol producing hydrogen and magnesium ethanolate.
When all of the magnesium has been consumed, the remainder of the absolute alcohol is added, refluxed for 30 minutes, and distilled directly into the planned storage vessel. The resulting ethanol should be better than 99.95%. See the Video 'Making super dry alcohol'.
Step 2
Sodium ethoxide catalyst is again needed in the reaction vessel, and this time 47g of the monosubstituted ester from Step 1 is converted to a di-substituted ester by reflux (or reaction in an autoclave) with the second side chain. For the synthesis of Amytal, this second sidechain is 1-bromo-3 methylbutane. In the case of Nembutal, it is 2-bromopentane, in each case 38g is required.
At the end of this stage the di-substituted malonate is removed again by vacuum distillation. This is 3-methyl-butyl-ethyl malonic ester in the case of Amytal synthesis; 1-methyl butyl-
ethyl malonic ester if Nembutal is being manufactured.
Step 3
Sodium ethoxide is again needed in the reaction vessel. For this final step 58g of the di-substituted malonate from step 2 is allowed to react with 15g of dry urea that has been dissolved in hot dry alcohol. The mixture is stirred and heated under reflux. After 4 hours, the excess alcohol is boiled off and the residue dissolved in water and acidified
(with dilute hydrochloric acid) to precipitate the insoluble barbiturate crystals which can be washed and dried.
''
Best regards!!! and thank you a lot!!!
And also in the book sodium ethoxide is prepared in situ in the reaction vessel for the step 1 reaction, but he have access to 20% sodium ethoxide solution in absolutely dry ethanol or simply sodium ethoxide, so he can pass through the step of making it in situ.
So if anyone can tell how much sodium ethoxide is produced also in step 1 to directly add the already made sodium ethoxide will be very appreciated.
This is the ''Peacefull Pill Project'' part of the book where the synthesis is written:
''
Step 1
In the case of the target barbiturates, Nembutal or Amytal, the first sidechain to be attached to the di-ethyl malonate is an ethyl halide, usually ethyl bromide is used. To form the mono-sustituted malonic ester, ethyl bromide is heated with the di-ethyl malonate in the presence of the required catalyst - the base, sodium ethoxide.
The catalyst may be purchased or made as part of the process. To make the required ethoxide add 5.7g of metallic sodium that has been cleaned by passing through a press - see 'Betty cooks with Sodium' - and 125m1 of very dry alcohol.
Into this mixture of dry alcohol and sodium ethoxide add 38m1 of di-ethyl malonate and 26g of bromoethane. Heat is applied and the mixture stirred using a magnetic stirrer. In an open system a reflux condenser must be fitted and a calcium chloride guard tube used to ensure no contamination by atmospheric moisture.
Note: Super Dry Alcohol
Alcohol (ethanol) of the required dryness can be made using methylated spirits as the starting point (95.6% alcohol). Absolute ethanol (>99.5%) is obtained by heating this under reflux with dry (recently fired) calcium oxide. To significantly improve the yield in the synthesis of barbiturates, even dryer alcohol is required. To remove more of the water, thereby converting the 99.5% ethanol to 'super dry' alcohol (>99.8%), use 5gm of magnesium turnings with 0.5gm of iodine in a boiling vessel. Let the magnesium react with —50m1 of the 99.5% ethanol producing hydrogen and magnesium ethanolate.
When all of the magnesium has been consumed, the remainder of the absolute alcohol is added, refluxed for 30 minutes, and distilled directly into the planned storage vessel. The resulting ethanol should be better than 99.95%. See the Video 'Making super dry alcohol'.
Step 2
Sodium ethoxide catalyst is again needed in the reaction vessel, and this time 47g of the monosubstituted ester from Step 1 is converted to a di-substituted ester by reflux (or reaction in an autoclave) with the second side chain. For the synthesis of Amytal, this second sidechain is 1-bromo-3 methylbutane. In the case of Nembutal, it is 2-bromopentane, in each case 38g is required.
At the end of this stage the di-substituted malonate is removed again by vacuum distillation. This is 3-methyl-butyl-ethyl malonic ester in the case of Amytal synthesis; 1-methyl butyl-
ethyl malonic ester if Nembutal is being manufactured.
Step 3
Sodium ethoxide is again needed in the reaction vessel. For this final step 58g of the di-substituted malonate from step 2 is allowed to react with 15g of dry urea that has been dissolved in hot dry alcohol. The mixture is stirred and heated under reflux. After 4 hours, the excess alcohol is boiled off and the residue dissolved in water and acidified
(with dilute hydrochloric acid) to precipitate the insoluble barbiturate crystals which can be washed and dried.
''
Best regards!!! and thank you a lot!!!
