75-98-9

Basic information

• Product Name: 2,2-Dimethylpropanoic acid
• Synonyms: Pivalicacid (7CI,8CI);2,2,2-Trimethylacetic acid;2,2-Dimethylpropanoic acid;2,2-Dimethylpropionic acid;NSC 65449;Neopentanoic acid;Neovaleric acid;Trimethylacetic acid;Trimethylmethanecarboxylic acid;Versatic 5 acid;tert-Pentanoic acid;a,a-Dimethylpropionic acid;Propanoic acid,2,2-dimethyl-
• CAS NO: 75-98-9
• Molecular Formula: C₅H₁₀O₂
• Molecular Weight: 102.1317
• EINECS: 200-922-5
• Mol File: 75-98-9.mol
• Article Data: 168

Chemical Properties

• Melting Point: 33-36℃
• Boiling Point: 166.2 °C at 760 mmHg
• Flash Point: 68.3 °C
• Appearance: white crystalline low melting mass
• Density: 0.965 g/cm³
• Vapor Pressure: 0.907mmHg at 25°C
• Water Solubility: 25 g/L (20℃)
• CAS DataBase Reference: 2,2-Dimethylpropanoic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 2,2-Dimethylpropanoic acid(75-98-9)
• EPA Substance Registry System: 2,2-Dimethylpropanoic acid(75-98-9)

Safety Data

• Hazard Codes: C:Corrosive
• Statements: R21/22:; R34:
• Safety Statements: S26:; S36/37/39:; S45:
• RIDADR: 3261
• HazardClass: 8
• PackingGroup: II
• Hazardous Substances Data: 75-98-9(Hazardous Substances Data)

Usage

General Description

2,2-Dimethylpropanoic acid is an organic compound with the chemical formula C6H12O2. It is a carboxylic acid, characterized by a branched structure and two methyl groups attached to the carbon at the alpha position. 2,2-Dimethylpropanoic acid is commonly used as a building block in organic synthesis and pharmaceutical manufacturing. It is a colorless, viscous liquid with a pungent odor and is soluble in most organic solvents like alcohols and ethers. It is also known by its IUPAC name, 2,2-dimethylpropionic acid, and its CAS number is 116-09-6. 2,2-Dimethylpropanoic acid is often used as a reagent or intermediate in the production of various industrial and pharmaceutical products. Additionally, it has a low toxicity and is not considered to be harmful to human health or the environment.

InChI:InChI=1/C5H10O2/c1-5(2,3)4(6)7/h1-3H3,(H,6,7)/p-1

Synthetic route

Methyl pivalate (598-98-1) → selenoanisole (4346-64-9) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With benzeneselenolate ion Mechanism; reaction of esters with phenyl selenide anion;	A 100% B 98%
With Benzeneselenol; sodium hydride 1.) THF, 2.) HMPA, 6 h, reflux; Yield given. Multistep reaction. Yields of byproduct given;

pivalaldehyde (630-19-3) → Trimethylacetic acid (75-98-9)

Conditions	Yield
With C4H11FeMo6NO24(3-)*3C16H36N(1+); water; oxygen; sodium carbonate at 50℃; under 760.051 Torr; for 8h; Green chemistry;	99%
With 4H3N*4H(1+)*CuMo6O18(OH)6(4-); water; oxygen; sodium carbonate at 50℃; under 760.051 Torr; for 12h;	99%
With C22H42CoN4O4(1+)*C4H10O*C24H20B(1-) In methanol; acetonitrile at 25℃;	94%

3,3-dimethyl-butan-2-one (75-97-8) → Trimethylacetic acid (75-98-9)

Conditions	Yield
With tetrachloromethane; sodium hydroxide; N-benzyl-N,N,N-triethylammonium chloride In dichloromethane for 2h;	96%
With sodium hypochlorite; lithium hypochlorite In ethanol at 77℃; for 8h;	84%
With sodium hypochlorite; sulfuric acid In water	83.8%

2,2-dimethylpropionamide (754-10-9) → Trimethylacetic acid (75-98-9)

Conditions	Yield
With benzene-1,2-dicarboxylic acid at 250℃; under 7600 Torr; for 0.25h; microwave irradiation;	96%
With phthalic anhydride at 240 - 250℃; under 3040 Torr; for 0.583333h; Hydrolysis;	91%
With niobium(V) oxide; water In neat (no solvent) for 20h; Reflux; Inert atmosphere;	91%
With sulfuric acid; cis-nitrous acid at 25℃; Thermodynamic data; E; other aliphatic and aromatic primary amides;

2,2-dimethyl-propanol-1 (75-84-3) → Trimethylacetic acid (75-98-9)

Conditions	Yield
With 1-hydroxy-1H-1,2,3-benziodoxathiole 1,3,3-trioxide; Oxone; cetyltrimethylammonim bromide In water at 100℃; for 24h; Green chemistry; chemoselective reaction;	93%
With sodium hypochlorite; nickel dichloride In dichloromethane; water at 0 - 20℃; for 4h;	88%
With 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate In water; acetonitrile at 20℃; for 480h;	88%

2,2-dimethylpropionic acid, 4-methoxybenzyl ester → Trimethylacetic acid (75-98-9)

Conditions	Yield
With N1,N1,N12,N12-tetramethyl-7,8-dihydro-6H-dipyrido[1,2-a:2,1'-c][1,4]diazepine-2,12-diamine In N,N-dimethyl-formamide for 24h; Inert atmosphere; Glovebox; UV-irradiation;	83%

(4R-cis)-6-(2-aminoethyl)-4-(2-hydroxyethyl)-2,2-dimethyl-1,3-dioxane pivalate salt + 2-[2-(4-fluorophenyl)-2-oxo-1-phenylethyl]-4-methyl-3-oxopentanoic acid phenylamide (125971-96-2) → Trimethylacetic acid (75-98-9)

Conditions	Yield
In toluene for 27h; Heating / reflux;	80.1%

indole (120-72-9) + 2,2-dimethylpropanoic anhydride (1538-75-6) → 1-(1H-indol-3-yl)-2,2-dimethyl-1-propanone (69622-35-1) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With Cl(1-)*C5H14NO(1+)*3ZnCl2 at 120℃; for 0.166667h; Friedel-Crafts Acylation; Microwave irradiation; Green chemistry; regioselective reaction;	A 79% B n/a

3,5-Dimethoxybenzyl pivalate (157843-81-7) → 1,3-dimethoxy-5-methylbenzene (4179-19-5) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With N1,N1,N12,N12-tetramethyl-7,8-dihydro-6H-dipyrido[1,2-a:2,1'-c][1,4]diazepine-2,12-diamine In N,N-dimethyl-formamide for 24h; Inert atmosphere; Glovebox; UV-irradiation;	A 9% B 78%

3,4,5-Trimethoxybenzyl pivalate (157843-82-8) → 3,4,5-trimethoxytoluene (6443-69-2) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With N1,N1,N12,N12-tetramethyl-7,8-dihydro-6H-dipyrido[1,2-a:2,1'-c][1,4]diazepine-2,12-diamine In N,N-dimethyl-formamide for 24h; Inert atmosphere; Glovebox; UV-irradiation;	A 11% B 73%

methanol (67-56-1) + 1-naphthylmethyl 2,2-dimethylpropanoate (72681-59-5) → 1-neopentylnaphthalene (20411-45-4) + 1-(methoxymethyl)naphthalene (5903-23-1) + Trimethylacetic acid (75-98-9)

Conditions	Yield
at 20℃; Rate constant; Quantum yield; Irradiation;	A 9% B 71% C n/a

tert-butyl isocyanide (630-18-2) → 3,4,5,6-tetrafluorophthalimide (652-11-9) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With 3,4,5,6-tetrafluorophthalic acid at 180℃; for 120h;	A n/a B 70%

2,2-dimethyl-propanol-1 (75-84-3) → neopentyl pivalate (5340-26-1) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With sodium bromate; sodium hydrogensulfite for 2h; Ambient temperature;	A 70% B 4%

2,2-dimethylpropionamide (754-10-9) → 3,4,5,6-tetrafluorophthalimide (652-11-9) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With 4,5,6,7-tetrafluoroisobenzofuran-1,3-dione at 155℃; for 120h;	A n/a B 68%

N-neopentylaniline (7210-81-3) → N-(neopentylidene)aniline (26029-60-7) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With iron(III) porphyrin(1+); iodosylbenzene In dichloromethane at 0℃; for 4h;	A 65% B 9%

2,2-dimethyl-propanol-1 (75-84-3) → pivalaldehyde (630-19-3) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With tert.-butylhydroperoxide; chromium tetra(tert-butoxide) In benzene at 20℃; for 24h;	A 15% B 61%

trimethylpyruvic acid (815-17-8) → Trimethylacetic acid (75-98-9)

Conditions	Yield
With quinoline; oxygen; cobalt(II) acetate; copper at 110 - 120℃; for 1.25h;	60%
With quinoline; oxygen; cobalt(II) acetate; copper at 110 - 120℃; for 1.25h; Product distribution; var. cat. syst.;
With silver(l) oxide
With chromic acid
With dihydrogen peroxide

t-Bu-oxycarbonylcobalt tetracarbonyl → dicobalt octacarbonyl (15226-74-1, 61091-28-9, 61117-58-6) + tetracobaltdodecacarbonyl (15041-50-6) + carbon dioxide (124-38-9) + tert-butyl alcohol (75-65-0) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With carbon monoxide thermal decompn. of alkoxycarbonylcobalt tetracarbonyl at 60°C at 1 bar of CO, further products;	A n/a B 60-70 C n/a D 60% E 30%

pivalaldehyde (630-19-3) → tert-butyl alcohol (75-65-0) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With dihydrogen peroxide; 7-(trifluoromethyl)-1,10-ethyleneisoalloxazinium chloride In water; acetonitrile at 85℃; for 18h;	A 40 %Spectr. B 60%

2-phenylpropane-1,2-diyl bis(2,2-dimethylpropanoate) (1426824-99-8) → isopropenylbenzene (98-83-9) + Trimethylacetic acid (75-98-9)

Conditions	Yield
With N1,N1,N12,N12-tetramethyl-7,8-dihydro-6H-dipyrido[1,2-a:2,1'-c][1,4]diazepine-2,12-diamine In N,N-dimethyl-formamide for 72h; Inert atmosphere; Glovebox; UV-irradiation;	A 21% B 59%

aniline (62-53-3) + Trimethylacetic acid (75-98-9) → N-pivaloylaniline (6625-74-7)

Conditions	Yield
With diphosphorus tetraiodide In tetrachloromethane; dichloromethane Heating;	100%
With TEA; diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate In various solvent(s) for 2h; Ambient temperature;	99%
With triethylamine; Phenyl N-phenylphosphoramidochloridate In dichloromethane for 1.5h; Ambient temperature;	91%

3,5-dimethylaminoaniline (108-69-0) + Trimethylacetic acid (75-98-9) → N-(3,5-dimethylphenyl)pivalamide (86489-67-0)

Conditions	Yield
With diphosphorus tetraiodide In tetrachloromethane; dichloromethane Heating;	100%

2,6-dimethylaniline (87-62-7) + Trimethylacetic acid (75-98-9) → 2,2-dimethyl-N-(2,6-dimethylphenyl)propionamide (39627-97-9)

Conditions	Yield
With diphosphorus tetraiodide In tetrachloromethane; dichloromethane Heating;	100%

benzylamine (100-46-9) + Trimethylacetic acid (75-98-9) → N-benzyl-2,2-dimethylpropanamide (26209-45-0)

Conditions	Yield
With diphosphorus tetraiodide In tetrachloromethane; dichloromethane Heating;	100%
With tetramethylorthosilicate In toluene at 110℃; for 20h; Inert atmosphere;	99%
With 4,5,6,7-tetrachlorobenzo[d][1,3,2]dioxaborole In o-xylene for 15h; Heating;	94%

2-mercaptothiazoline (96-53-7) + Trimethylacetic acid (75-98-9) → 3-pivaloyl-1,3-thiazolidine-2-thione (138459-91-3)

Conditions	Yield
With 2,6-dimethylpyridine; 2-chloro-1,3-dimethylimidazolinium chloride In dichloromethane at 20℃; for 72h; Acylation;	100%

Trimethylacetic acid (75-98-9) → lithium trimethylacetate (14271-99-9)

Conditions	Yield
With methyllithium In tetrahydrofuran; diethyl ether at 0℃; for 0.75h; Inert atmosphere;	100%
With lithium hydroxide monohydrate In methanol at 40℃; for 1h;	89%
With lithium hydroxide monohydrate In water at 140℃; Heating;	88%
With lithium hydroxide In water

diethylzinc (557-20-0) + Trimethylacetic acid (75-98-9) → zinc trimethylacetate

Conditions	Yield
In tetrahydrofuran at 0 - 25℃; for 1.5h; Inert atmosphere;	100%
In tetrahydrofuran at 0 - 22℃; Inert atmosphere; Schlenk technique;	100%
In tetrahydrofuran at 0 - 25℃; for 1.5h; Inert atmosphere;	100%

2-(2-nitrophenyl)but-3-en-1-ol (855743-28-1) + Trimethylacetic acid (75-98-9) → 2-(2-nitrophenyl)but-3-en-1-yl pivalate (1441228-44-9)

Conditions	Yield
With dmap; dicyclohexyl-carbodiimide In dichloromethane for 4h; Inert atmosphere; Reflux;	100%

Trimethylacetic acid (75-98-9) → magnesium trimethylacetate (123133-75-5)

Conditions	Yield
With dibutylmagnesium In tetrahydrofuran; hexane at 0 - 25℃; for 6.5h; Inert atmosphere; Schlenk technique;	100%
With dibutylmagnesium In tetrahydrofuran; hexane at 0 - 25℃; for 6.5h; Inert atmosphere; Schlenk technique;	100%

4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane (25015-63-8) + Trimethylacetic acid (75-98-9) → PivOBpin

Conditions	Yield
In toluene at 20℃; for 3.25h; Glovebox;	100%

benzyl alcohol (100-51-6) + Trimethylacetic acid (75-98-9) → benzyl pivalate (2094-69-1)

Conditions	Yield
With diphenylphosphinopolystyrene; diethylazodicarboxylate In tetrahydrofuran at 25℃; for 4h;	99%
With pyridine; 2,4,6-trinitrochlorobenzene for 3h;	95%
With triethylamine In dichloromethane 1.) 0 deg C; 2.) to room temperature and 1 h;	79%

N-hydroxyphthalimide (524-38-9) + Trimethylacetic acid (75-98-9) → 1,3-dioxoisoindolin-2-yl 3,3-dimethylbutanoate (84379-72-6)

Conditions	Yield
Stage #1: Trimethylacetic acid With dmap; dicyclohexyl-carbodiimide In tetrahydrofuran for 0.0166667h; Schlenk technique; Inert atmosphere; Stage #2: N-hydroxyphthalimide In tetrahydrofuran at 20℃; for 24h; Inert atmosphere; Schlenk technique;	99%
With dmap; diisopropyl-carbodiimide In dichloromethane at 20℃; for 5h;	98%
With dmap; dicyclohexyl-carbodiimide In dichloromethane at 20℃;	95%

N4-{3-[4-(3-aminopropyl)piperazino]propyl}-7-chloroquinolin-4-amine (497233-85-9) + Trimethylacetic acid (75-98-9) → N-(3-{4-[3-(7-chloro-quinolin-4-ylamino)-propyl]-piperazin-1-yl}-propyl)-2,2-dimethyl-propionamide

Conditions	Yield
With benzotriazol-1-ol; O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; N-ethyl-N,N-diisopropylamine In dichloromethane at 20℃; for 4h;	99%

(1S,4aR,5S,7aS)-7-[(2,2-dimethyl-1-oxopropoxy)methyl]-1,4a,5,7a-tetrahydro-5-hydroxycyclopenta[c]pyran-1-yl 2,3,4,6-tetrakis-O-(2,2-dimethyl-1-oxopropyl)-β-D-glucopyranoside (532976-84-4) + Trimethylacetic acid (75-98-9) → (1S,4aR,5R,7aS)-5-(2,2-dimethyl-1-oxopropoxy)-7-[(2,2-dimethyl-1-oxopropoxy)methyl]-1,4a,5,7a-tetrahydrocyclopenta[c]pyran-1-yl 2,3,4,6-tetrakis-O-(2,2-dimethyl-1-oxopropyl)-β-D-glucopyranoside (532976-86-6)

Conditions	Yield
With triphenylphosphine; diethylazodicarboxylate In tetrahydrofuran at 0 - 20℃; for 1.91667h; modified Mitsunobu reaction;	99%

2-chloro-3-(4-tetrahydropyranyl)-3-oxopropanoic acid methyl ester (874910-51-7) + Trimethylacetic acid (75-98-9) → 2-pivaloyloxy-3-(4-tetrahydropyranyl)-3-oxopropanoic acid methyl ester

Conditions	Yield
With triethylamine In N,N-dimethyl-formamide at 20℃; for 16h;	99%

bis(η-cyclopentadienyl)hydridophenyltungsten + Trimethylacetic acid (75-98-9) → bis(cyclopentadienyl)(hydrido)(pivalato)tungsten(IV)

Conditions	Yield
In diethyl ether byproducts: C6H6; addn. of diethyl ether to a mixture of the starting complex and the carboxylic acid, stirring at room temp. for 48 h, all steps under N2 or Ar; filtn. of ppt.;	99%

3,5-dimethyl-1H-pyrazole (67-51-6) + cobalt(II) acetate (71-48-7, 917-69-1, 5931-89-5, 55881-15-7, 68931-68-0, 68931-69-1, 93029-27-7) + Trimethylacetic acid (75-98-9) → bis(3,5-dimethylpyrazole)bis(trimethylacetato)bis(μ-N,N'-3,5-dimethylpyrazolato)dicobalt(II) (615251-39-3)

Conditions	Yield
With triethylamine In hexane byproducts: (C2H5)3NHOOCC(CH3)3; under Ar atm.; aq. cobalt acetate and pivalic acid were fused at 165°C; cooled; excess of ligand, Et3N added; 22°C; suspn. dissolved in hexane; allowed to stand for 1 d at 5°C; crystals washed (hexane); dried in flowing Ar; elem. anal.;	99%

9-borabicyclo[3.3.1]nonane dimer (21205-91-4) + Trimethylacetic acid (75-98-9) → 9-pivaloyloxy-9-borabicyclo[3.3.1]nonane, dimer (169695-35-6)

Conditions	Yield
In 1,2-dimethoxyethane byproducts: H2; (inert atmosphere); 40°C, 2 d; evapn. (20°C/0.01 Torr); elem. anal.;	99%

pyridine (110-86-1) + [Ce(o-(tert-butyl)phenol(-H))3(tetrahydrofuran)3] (950990-97-3) + Trimethylacetic acid (75-98-9) → [Ce(o-(tert-butyl)phenol(-H))(μ-trimethylacetate)(μC-trimethylacetate)(pyridine)2]2 (950991-05-6)

Conditions	Yield
In pyridine under inert atm., Schlenk techniques; soln. of Ce compd. (0.32 mmol) andacid (0.65 mmol) stirred for 12 h; crystd. on storage, elem. anal.;	99%

Upstream product

• 123-91-1 1,4-dioxane 
• 938-16-9 2,2-dimethylpropiophenone 
• 865-47-4 potassium tert-butylate 
• 110-86-1 pyridine 
• 854401-80-2 4,7-dibromo-2,2,9,9-tetramethyl-decane-3,8-dione 
• 141-78-6 ethyl acetate 
• 56-23-5 tetrachloromethane 
• 5950-19-6 3-chloro-3-methyl-2-butanone 
• 75-84-3 2,2-dimethyl-propanol-1 
• 52329-73-4 2-hydroxy-2,3,3-trimethylbutanal 
• 4388-88-9 pivalil 
• 815-17-8 trimethylpyruvic acid 
• 64-18-6 formic acid 
• 75-65-0 tert-butyl alcohol 

Downstream Products

• 20409-48-7 2,2-dimethyl-1-(2-thienyl)-1-propanone 
• 75-84-3 2,2-dimethyl-propanol-1 
• 1538-75-6 2,2-dimethylpropanoic anhydride 
• 630-19-3 pivalaldehyde 
• 630-18-2 tert-butyl isocyanide 
• 6625-74-7 N-pivaloylaniline 
• 27976-09-6 Thiosulfuric acid S-[2-(2,2-dimethyl-propylamino)-ethyl] ester 
• 67662-96-8 2-phenethyl pivalate 
• 60159-35-5 2-tert-butyl-4-acetylpyridine 
• 115-11-7 isobutene 
• 75-65-0 tert-butyl alcohol 
• 129584-32-3 cis-1-chloro-4-pivaloyloxy-2-cyclohexene 
• 2094-69-1 benzyl pivalate 
• 3459-92-5 DBC 

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