dimethylsulfoxide

2

Dopamine C8H11NO2

  • Appearance: Colorless solid
  • Molar Mass: 153.18 g/mol
  • Density: 1.26 g/cm3 (at 20°, solid)
  • Melting Point: 128°C
  • Boiling Point: decomposes 
  • pKa: n/a (an anime, so it’s an organic base). 

Dopamine is a neurotransmitter in humans and animals. It has a major role in reward-motivation. Dopamine is released into the brain in increased levels when “rewards” are completed. Several addictive drugs play on this like cocaine and amphetamine-based drugs. Outside the nervous system and the brain, dopamine does have some uses in the body like an inhibitor to norepinephrine in blood cells and increasing sodium excretion. Dopamine gets it’s name from it’s metabolite precursor, L-DOPA. Dopamine however cannot breach the blood/brain barrier, however it still is useful if it’s needed to be intravenously infected. In the body, it’ broken down by the enzyme monoamine oxidase via oxidation. However it can also be autooxidized by direct oxygen, resulting in quinones and free radicals. One of dopamine’s nicknames is the “pleasure chemical”. 

2

 Diazepam (valium) C16H13ClN2O

  • Appearance: White solid
  • Molar Mass: 284.74 g/mol
  • Density: 1.08 g/cm3 (at 20°, solid)
  • Melting Point: 125-126°C
  • Boiling Point: n/a 
  • pKa: n/a

Diazepam is a benzodiazepine and well-known sedative used to combat all sorts of conditions like anxiety, depression, seizures, and even restless leg syndrome. While having a wide range of uses, it also comes with some bad paradoxical effects like actually worsening seizures. It is most well known for subduing anxiety attacks since diazepam rapidly sets in. It should be noted that it is highly advised not to overuse diazepam due to easy dependency formation. 

Naming of compounds

Hey everyone! I’m working on some posts for functional groups and I realized how in-depth I’d have to get to the naming of organic structures. If I get enough people asking though I will do a /giant/ post on IUPAC naming. 

If anyone’s interested in that, give me a heads up. Also message me some compounds/reactions you’re interested in seeing here! Much appreciated!

2

Acetaldehyde C2H4O

  • Appearance: Colorless liquid
  • Molar Mass: 44.05 g/mol
  • Density: 0.784 g/cm(at 20°C)
  • Melting Point: -123.37°C
  • Boiling Point: 20.2°C 
  • pKa: 13.57

Acetaldehyde is one of the most important aldehydes, occuring in coffee and bread. It’s more well known as being the metabolite of ethanol by alcohol dehydrogenase, thought to be the main cause of hangovers. It undergoes keto-enol tautomerism, but only a small fraction of acetaldehyde is in the enol tautomer. Acetaldehyde used to be a precursor to acetic acid, however now it’s more important as a precursor to pyridine derivatives like pentaerthritol. It’s toxic when applied for extended periods, is an irritant on the skin, eyes, and mucous membranes, and is a possible carcinogen. It’s found smoke from cannabis and tobacco.

5

Alkanes, Alkenes, and Alkynes

Alkanes are hydrocarbons that are saturated (completely covered in hydrogens, lacking in any double or triple bonds). The formula for an alkane is CnH2n+2. Alkanes have a bond angle of 109.5° (since alkanes/saturated hydrocarbons are only sp3 carbons). A alkane hanging off of a compound as a functional group is called an alkyl group.

Alkenes are unsaturated hydrocarbons that include at least one carbon-carbon double bond. The formula for an alkene is CnH2n. Alkenes have a bond angle of 120°, giving the spcarbon a planar shape. Alkenes are very reactive and can react in numerous ways. They’re conformers are noted by E/Z notation or by cis/trans notation. Two special groups stem from alkenes and those are vinyl and allyl groups. a vinyl group is when a carbon bonds directly to the carbon participating in a C-C double bond. An allyl group is when a carbon bonds to a vinylic carbon. The functional group name for an alkene is an alkenyl group.

Alkynes are unsaturated hydrocarbons that include at least one carbon-carbon triple bond. The formula for an alkyne is CnH2n-2. Alkynes are very reactive and because of their double pi bonds, the bond angle for an alkyne is 180°, which makes cyclic structures very difficult and unstable until . The compound benzyne (a benzene ring with a triple bond) is thought to be an intermediate structure in some reactions and is highly unstable. Like alkenes, alkynes have a few functional groups related to them. One is the propargyl group, which is the alkyne variant of the a vinyl group (a carbon connected to one of the carbons of the C-C triple bond.) The homopropargyl group is the alkynl analogue of an allyl group (a carbon bonded to a propargyl group). The functional group name for an alkyne is an alkynl group. 

2

Acid-catalyzed addition of water to an alkene and an alkyne

In an acid-catalyzed addition of water to an alkene, the product will be a markovnikov addition where water is added to the more stable carbocation to form an alcohol. The water is protonated by the sulfuric acid (or any suitable acid) and is then deprotonated by the alkene. This forms a carbocation in the more stable position. In the case above, the middle carbon is becomes a 2° carbocation, where as a terminal carbon would form a 1° carbocation (unstable). The water attacks the carbocation and is then deprotonated by the surrounding water, forming the alcohol. The reaction takes place in water, which is why water can just come in and protonate and deprotonate. 

The acid-catalyzed addition of water to an alkyne is not as simple. As before, the water is protonated by the sulfuric acid and is attacked by the alkyne. However here, the alkyne and water form a sort of “pi-complex” at the hydrogen. Here, there is partial positive charges forming at both ends of the triple bond. Another water molecule comes and attacks the alkyne at the internal carbon, because here the partial positive charge from the pi-complex is more stable due to being a 2° carbon (where as the terminal carbon is a 1° carbon). This second water molecule breaks the pi-complex and forms a protonated enol, an alkene with a double bond. The water then deprotonates the enol and it then is tautomerized from an enol to a ketone. The electrons on the hyrdoxyl group flow down and form a protonated carbonyl (a carbon-oxygen double bond). This is then deprotonated by water to form the stable product, a ketone. The idea behind keto-enol tautomerism is that there is a rapid equilibrium between the enol and keto form of the compound, however there is more of the keto form due to it being the more stable. 

2

Disulfiram C10H20N2S4

  • Appearance: Beige powder
  • Molar Mass: 296.539 g/mol
  • Density: 1.3 g/cm3
  • Melting Point: 71.5°C
  • Boiling Point: 117°C (at 17 mmHg)
  • pKa: n/a

Disulfiram is a drug that is used to support chronic alcoholism by blocking the enzyme that breaks down acetaldehyde to acetic acid, causing a build up. Acetaldehyde is the metabolite of ethanol after it’s been broken down by alcohol dehydrogenase. The build up of acetaldehyde is what is generally thought to be the cause of a “hangover”. Thus, disulfiram causes a larger build up of acetaldehyde, which leads to a more severe hangover. This effect is what can lead to the breaking of chronic alcoholism.

2

Adamantane C10H16

  • Appearance: White/off-white powder
  • Molar Mass: 136.23 g/mol
  • Density: 1.08 g/cm3 (at 20°, solid)
  • Melting Point: 270°C
  • Boiling Point: sublimes 
  • pKa: n/a

Adamantane is a crystalline compound and is the simplest diamondoid. It consists of four cyclohexane rings in the “armchair”. The arrangement of atoms in adamatane is the same as a diamond crystal. Adamantane is unique in that it is rigid and almost free of strain and stress. It was first synthesized from Meerwein’s ester, however this process resulted in very low yield. Adamantane cations can be produced and are highly stable, and this is due to a three-dimensional aromaticity (homoaromaticity). Since it is an unfunctionalized hydrocarbon, it’s uses are limited, however aminoadamantanes have come up in medicine as an antiviral for influenza (though this has been discontinued) and as an antiparkinsonian drug. 

2

Diethyl Ether C4H10O

  • Appearance: Colorless liquid
  • Molar Mass: 74.12 g/mol
  • Density: 0.7132 g/cm3
  • Melting Point: -116.4°C
  • Boiling Point: 34.6°C
  • pKa: -3.5 (conjugate acid)

Diethyl ether, also known as just “Ether”, is a flammable, volatile liquid used primarily as a solvent. It also has uses as a general anesthetic with narcotic properties but it’s use has been discontinued for safer, halogenated anesthetics. It has a major drawback of causing psychoactive addiction, called etheromania. 

2

Addition of Hydrogen Halides to Alkenes and Alkynes

When a hydrogen halide (bromide or chloride) to an alkene, the double bond attacks the hydrogen, forming a carbocation on the more stable carbon (generally always a 2° or 3°) and a bromide ion. The bromide ion reacts with the newly formed carbocation to form the alkyl halide. it’s a very simple reaction.

The exact same thing occurs when reactings an alkyl halide with an alkyne, however after it’s been reacted, it can have a second hydrogen halide added to it, resulting in a geminal alkyl halide. When the second hydrogen halide is added, it undergoes the same reaction, resulting in the diaddition shown. 

edit: oops fixed the direction of the arrows in the carbocation/bromide part. Thanks to rougelette for pointing it out!!

2

(−)-trans9-tetrahydrocannabinol (THC) C21H30O2

  • Appearance: clear solid crystal (cold), waxy, viscous (warm)
  • Molar Mass: 314.469 g/mol
  • Density: n/a
  • Melting Point: n/a
  • Boiling Point: 250°C
  • pKa: n/a
  • (literally could not find ANY data for this)

Tetrahydrocannabinol is the main psychoactive component of cannabis. It has some analgesic effects and is known to increase appetite and enjoyment of food. It’s most famous for it’s effects on cognitive functions, leading to the substance being banned in many areas. These effects can actually be lessened by opioid receptor antagonists like naloxone. While being an illegal substance, the medical properties of THC have been investigated and seems to have many beneficial properties for those undergoing chemotherapy, people suffering from AIDS, multiple sclerosis, and neurological disorders like Tourette syndrome. The main metabolite of THC is 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC), where the methyl group gains a hydroxy group. 

2

Cis/Trans and E/Z Naming

  • Cis - same side
  • Trans - opposite side
  • E - opposite size (think eppesite side)
  • Z - same side (think zame zide)

When you name alkenes, you have to account for the isomer that you’re talking about. Cis/Trans naming is used for alkenes in chains or disubstituted alkenes like the top row of alkenes, 2-butene and 3-hexene. Cis/Trans and E/Z could be applied to these. The cis isomer is when the two hydrogens are on the same side of the double bond and the two alkyl chains are on the other. The trans isomer is when they’re switched. So going across the image above, the structures would be:

  • Trans-2-butene or (E)-2-butene
  • Cis-2-butene or (Z)-2-butene
  • Trans-3-hexene or (E)-3-hexene
  • Cis-3-hexene or (Z)-3-hexene

Once there is more than one substituent on each sp2 carbon, the cis/trans naming cannot be used. E/Z naming is essentially the same thing, however it’s based on the “weight” and “heaviness” of the substituents. The heavier the substituent, the higher it ranks. When judging how to name E/Z, the attachments on each sp2 carbons are identified, never judge across the double bond. Only compare the two substituents connected to the same carbon, as circled in the image above. The heavier one is chosen. In the second row, there is:

  • (E)-2,3-dibromo-2-butene
  • (Z)-2,3-dibromo-2-butene
  • (E)-3,4-dimethyl-3-hexene
  • (Z)-3,4,-dimethyl-3-hexene

Issues arise when the same substituent is connected to the same carbon like the first two structures in the third row. The first structure has two ethyl groups coming off the sp2 carbon and in the second one, there are two hydrogens on the sp2 carbon. This leaves it so that there can’t be isomers of the structure. Underneath, on the last row, is maleic and fumaric acid. These two are isomers of each other and are common examples of E/Z isomers. The last structure is (Z)-4-methyl-1,4-hexadiene. You’ll notice that there are two double bonds in the structure, but only one of them can be an E/Z. Since the terminal double bond has two hydrogens, it’s ineligible to be an isomer. 

(sorry for the long post, I hope this helps!!)

2

Methylamine CH5N

  • Appearance: Colorless gas
  • Molar Mass: 31.06 g/mol
  • density: 694 kg/m3
  • Melting Point: -93.10 °C
  • Boiling Point: -6.6°C 
  • pKb: 3.36

Methylamine is a derivative of ammonia and is the simplest primary amine. It’s commonly sold as anhydrous gas in metal containers. It’s a relatively easy compound to synthesis in lab, being a simple reaction between methanol and ammonia. Methylamine is a great nucleophile that’s also highly basic with little to no hindrance. Liquid methylamine has solvent properties similar to ammonia. It is toxic and listed as a List 1 Precursor chemical by the DEA since it’s well known for it’s use in the production of methamphetamine. 

2

Ethanol (alcohol, spirits) C2H5OH

  • Appearance: Colorless liquid
  • Molar Mass: 46.07 g/mol
  • Density: 0.789 g/cm3
  • Melting Point: -114°C
  • Boiling Point: 78°C
  • pKa: 15.9

Ethanol is a primary, two carbon alcohol. It’s more famously known as “grain alcohol” or “spirits”. It’s a psychoactive drug, acting as a depressant on the central nervous system. It’s used in sanitation such as medical wipes, like other alcohols. Ethanol is also used as a solvent, and is miscible with water. This can be an issue as it forms an azeotrope (96% EtOH and 4% water) which makes it difficult to obtain 100% pure ethanol. A well known way to obtain ethanol is by the fermentation of sugars and also by distilling the fermented sugars to concentrate ethanol content. Ethanol is metabolized into acetaldehyde by the enzyme alcohol dehydrogenase.

2

Tetrahydrofuran (THF) C4H8O

  • Appearance: Colorless liquid
  • Molar Mass: 72.11 g/mol
  • Density: 0.8892 g/cm3
  • Melting Point: -108.4°C
  • Boiling Point: 66°C
  • pKa: n/a

THF is a 5 atom heterocyclic compound and is a constitutional isomer of diethyl ether. It’s a common solvent in the lab as one of the more polar ether solvents. It’s not considered to be excessively toxic but it is known to penetrate the skin and cause rapid dehydration. It can also form explosive peroxides. THF is used as a main solvent in hydroboration-oxidation to form primary alcohols. It’s also used to dissolve polymers and is a precursor to many polymers.

The Grignard reagents are a great pathway to understand and are a good start to organometallic chemistry. In RED is the formation of a basic Grignard reagent. Using a organohalide like bromobenzene, the Grignard reagent will form by adding fresh magnesium in dry Diethyl ether (or just an aprotic solvent). The reagent is made when the magnesium inserts between the benzene and the bromide, forming the benzene-magnesium bromide compound seen above. However it’s commonly drawn with a covalent bond going from the magnesium to the benzene but in reality a carbanion is formed at that spot and the bond acts in between a covalent and an ionic bond. This lets the Grignard act as a great nucleophole.

The BLUES text shows the synthesis of triphenylmethanol by reacting two equivalents of the newly made Grignard reagent with one equiv. of ethyl benzoate. The nucleophiles are very attracted to the carbon in the ester and attack it, sending the electrons up the oxygen and forming a tetrahedral intermediate. The oxygen sends down the electrons to reform the carbonyl and shoot off the ethoxide group, which is a better leaving group and anything else at the moment. We then form a diphenyl ketone which is attacked by the second equivalent of Grignard. Once it forms the tetrahedral intermediate, however, nothing leaves easily and the oxygen is protonated via acid work up.

I messed up slightly by not making the arrows go both ways since the phenyl rings can get knocked off and then reattack but eventually it will push to the final product.

2

Acetylsalicylic acid (ASA, Aspirin) C9H8O4

  • Appearance: White solid
  • Molar Mass: 180.157 g/mol
  • Density: 1.40 g/cm3
  • Melting Point: 136°C
  • Boiling Point: 140°C (decomposes)
  • pKa: 2.98

Acetylsalicylic acid is an analgesic and antipyretic. It’s most well known as the main ingredient of Aspirin. It’s through to be effective at preventing certain cancers. it’s an acetyl derivative of salicylic acid. ASA is stable when dry but in the presence of moisture, it hydrolyses to acetic acid and salicylic acid. It’s not easily soluble in the stomach’s acidic conditions, delaying absorption of larger doses. 

3

Alcohols

An alcohol group one which a hydrogen of an alkane has been replaced by an -OH, hydroxyl group. They are classified as Primary, Secondary, or Tertiary (1°, 2°, 3°). The “R” designation indicates a continued alkyl chain or group. The number of alkyl groups connected to the carbon containing the -OH group determines if it’s primary, secondary, or tertiary.

IUPAC naming of alcohols is to drop the -e of the alkyl chain (ethane -> ethanol). The informal way to name an alcohol is to use the alkyl group connected to the alcohol and add “alcohol” to the end. (such as ethyl alcohol, isopropyl alcohol, only works for smaller alcohols, otherwise they have an informal name given to them).

Alcohols are known for having a kind of biting, sharp smell. They’re polar molecules due to the -OH group and can hydrogen bond. They have a plethora of uses, especially as an antiseptic and solvent. They also undergo plenty of reactions like oxidation to aldehydes, and further oxidation to carboxylic acid. They can also be dehydrated by sulfuric acid and heat. -OH is not a good leaving group for nucleophilic substitution with an alkyl halide, but they react well with hydrogen halides, that “activate” the alcohol by protonating it, enabling it to leave easily.