tangent
01-10-10, 19:33
I'm really hopeful this thread takes off - it's a potentially very interesting one.
I don't know that much organic chemistry, but I am aware that most major drugs are based on plant extracts. The tricky part here is analytical chemistry, as concentrations very widely. Solvent extraction would be the norm, with the easiest available solvent being ETOH. So for starting products for organic synthesis and extraction, we have solvents, oils, petroleum products urea and aspirin And that's about where my knowledge runs out. So the question is what starting materials should be stocked to make other chemicals for organic synthesis with an eye toward eventually ending up with pharmaceuticals?
Maybe I'm looking at this backwards and we should be asking what drugs can be practically synthesized and work backwards - don't know... How about starting at both ends and working toward the middle.
Anyway, here are some notes on making chemicals from chemicals for inorganic compounds:
Acid + base → salt + water
Acid + metal carbonates, hydroxides, or oxides → metal salts
with the only secondary products being carbon dioxide gas (for the carbonates) or water (for the hydroxides and oxides).
Bases can also be reacted directly with some
metals to form metallates (salts in which a metal-ion complex forms the anion).
Strong bases can be reacted directly with some
nonmetals to produce salts. For example, elemental sulfur can be reacted with a
solution of sodium hydroxide to produce sodium polysulfide
most metals can be reacted directly with acids to form salts.
Acids –
acetic,
boric,
citric,
hydrochloric,
nitric,
oxalic,
phosphoric,
sulfuric
bases
aqueous ammonia,
potassium carbonate and hydroxide,
sodium carbonate and hydroxide
metal carbonates, hydroxides, or oxides
Metals and metal oxides
Halogen sources –
sodium hypochlorite (chlorine laundry bleach),
potassium bromide,
potassium iodide
are convenient sources of halide ions and elemental halides, both of which are useful for producing halide salts.
sodium chloride (table salt)
The lawn and garden store
ammonium nitrate pellets (34-0-0 fertilizer)
calcium nitrate,
sodium nitrate,
potassium nitrate,
potassium chloride,
potassium phosphate,
manganese sulfate,
Raw urea (46-0-0 fertilizer)
Technical grade calcium hydroxide (garden lime) and many others.
Pottery supply stores
Raw potassium carbonate (that name or pearl ash or potash)
hardware-store muriatic acid, which I buy by the gallon. That acid is
labeled as 31.45% HCl, or about 10.3 M. At 10.3 mol/L, 0.8 mol of HCl translates to
about 78 mL of acid.
technical
grade sodium hydroxide (crystal drain opener).
if you need some silver nitrate and have none in stock, you can
make your own by reacting a pre-1964 junk-silver coin or a junk piece of sterling
silver with nitric acid. Nearly all common forms of silver, including coins and
sterling, are an alloy of silver and copper, so reacting them with nitric acid
provides a mixed solution of silver nitrate and copper nitrate. You can isolate the
silver ions by adding an excess of sodium chloride (table salt) to precipitate the
silver ions, leaving the copper ions in solution. You can then filter the silver
chloride precipitate, wash it thoroughly, heat it to convert it to silver oxide, react it
with nitric acid, and evaporate the liquid to produce pure silver nitrate.
Agricultural and pottery chemicals are sufficiently pure for some
purposes. If you need higher purity, you can recrystallize them to whatever level of purity
you require, or use them to produce other chemicals and purify them at the product stage.
determine the best sources for the cation and anion you need. Ideally, you want to use
chemicals that are inexpensive and that you have in large supply. For that reason, it's a
good idea to keep basic chemicals in stock in relatively large quantities.
Think about purification before you start the synthesis. If possible, choose
reactants that will leave only the desired product in solution, with only hydrogen,
carbon dioxide, or water as byproducts.
If your only source of cations is a compound that reacts to yield an undesired
soluble byproduct, consider doing an intermediate synthesis to obtain that cation
in the form of the carbonate, hydroxide, or oxide.
Write balanced equations for the reaction(s) and calculate the stoichiometry
before you begin the synthesis. Ideally, you want to react exact stoichiometric
equivalents to avoid having your product contaminated by an excess of a (non-
volatile) reactant.
Ordinarily, you'll want to isolate the product in solid form, so minimize excess
water, which you'll have to evaporate.
If you require a high degree of purity, use recrystallization (once or repeatedly, if
necessary). Don't overlook the possibility that it may be easier to purify reactants
than the product. If so, recrystallize one or more of the reactants to maximize the
purity of the raw product
also, be sure to get a CRC printed in 1964 or earlier, as they had vastly better solubility tables that got stripped out of later editions.
Please chime in!
-t
I don't know that much organic chemistry, but I am aware that most major drugs are based on plant extracts. The tricky part here is analytical chemistry, as concentrations very widely. Solvent extraction would be the norm, with the easiest available solvent being ETOH. So for starting products for organic synthesis and extraction, we have solvents, oils, petroleum products urea and aspirin And that's about where my knowledge runs out. So the question is what starting materials should be stocked to make other chemicals for organic synthesis with an eye toward eventually ending up with pharmaceuticals?
Maybe I'm looking at this backwards and we should be asking what drugs can be practically synthesized and work backwards - don't know... How about starting at both ends and working toward the middle.
Anyway, here are some notes on making chemicals from chemicals for inorganic compounds:
Acid + base → salt + water
Acid + metal carbonates, hydroxides, or oxides → metal salts
with the only secondary products being carbon dioxide gas (for the carbonates) or water (for the hydroxides and oxides).
Bases can also be reacted directly with some
metals to form metallates (salts in which a metal-ion complex forms the anion).
Strong bases can be reacted directly with some
nonmetals to produce salts. For example, elemental sulfur can be reacted with a
solution of sodium hydroxide to produce sodium polysulfide
most metals can be reacted directly with acids to form salts.
Acids –
acetic,
boric,
citric,
hydrochloric,
nitric,
oxalic,
phosphoric,
sulfuric
bases
aqueous ammonia,
potassium carbonate and hydroxide,
sodium carbonate and hydroxide
metal carbonates, hydroxides, or oxides
Metals and metal oxides
Halogen sources –
sodium hypochlorite (chlorine laundry bleach),
potassium bromide,
potassium iodide
are convenient sources of halide ions and elemental halides, both of which are useful for producing halide salts.
sodium chloride (table salt)
The lawn and garden store
ammonium nitrate pellets (34-0-0 fertilizer)
calcium nitrate,
sodium nitrate,
potassium nitrate,
potassium chloride,
potassium phosphate,
manganese sulfate,
Raw urea (46-0-0 fertilizer)
Technical grade calcium hydroxide (garden lime) and many others.
Pottery supply stores
Raw potassium carbonate (that name or pearl ash or potash)
hardware-store muriatic acid, which I buy by the gallon. That acid is
labeled as 31.45% HCl, or about 10.3 M. At 10.3 mol/L, 0.8 mol of HCl translates to
about 78 mL of acid.
technical
grade sodium hydroxide (crystal drain opener).
if you need some silver nitrate and have none in stock, you can
make your own by reacting a pre-1964 junk-silver coin or a junk piece of sterling
silver with nitric acid. Nearly all common forms of silver, including coins and
sterling, are an alloy of silver and copper, so reacting them with nitric acid
provides a mixed solution of silver nitrate and copper nitrate. You can isolate the
silver ions by adding an excess of sodium chloride (table salt) to precipitate the
silver ions, leaving the copper ions in solution. You can then filter the silver
chloride precipitate, wash it thoroughly, heat it to convert it to silver oxide, react it
with nitric acid, and evaporate the liquid to produce pure silver nitrate.
Agricultural and pottery chemicals are sufficiently pure for some
purposes. If you need higher purity, you can recrystallize them to whatever level of purity
you require, or use them to produce other chemicals and purify them at the product stage.
determine the best sources for the cation and anion you need. Ideally, you want to use
chemicals that are inexpensive and that you have in large supply. For that reason, it's a
good idea to keep basic chemicals in stock in relatively large quantities.
Think about purification before you start the synthesis. If possible, choose
reactants that will leave only the desired product in solution, with only hydrogen,
carbon dioxide, or water as byproducts.
If your only source of cations is a compound that reacts to yield an undesired
soluble byproduct, consider doing an intermediate synthesis to obtain that cation
in the form of the carbonate, hydroxide, or oxide.
Write balanced equations for the reaction(s) and calculate the stoichiometry
before you begin the synthesis. Ideally, you want to react exact stoichiometric
equivalents to avoid having your product contaminated by an excess of a (non-
volatile) reactant.
Ordinarily, you'll want to isolate the product in solid form, so minimize excess
water, which you'll have to evaporate.
If you require a high degree of purity, use recrystallization (once or repeatedly, if
necessary). Don't overlook the possibility that it may be easier to purify reactants
than the product. If so, recrystallize one or more of the reactants to maximize the
purity of the raw product
also, be sure to get a CRC printed in 1964 or earlier, as they had vastly better solubility tables that got stripped out of later editions.
Please chime in!
-t