2181-22-8

Basic information

• Product Name: 2,2'-Methylenebis(5,5-dimethylcyclohexane-1,3-dione)
• Synonyms: 2,2'-Methylenebis(5,5-dimethyl-1,3-cyclohexanedione);2,2'-Methylenebis(5,5-dimethylcyclohexane-1,3-dione)
• CAS NO: 2181-22-8
• Molecular Formula: C₁₇H₂₄O₄
• Molecular Weight: 292.38
• Mol File: 2181-22-8.mol
• Article Data: 19

Chemical Properties

• Boiling Point: 453.8 °C at 760 mmHg
• Flash Point: 195.4 °C
• Appearance: /
• Density: 1.085 g/cm³
• CAS DataBase Reference: 2,2'-Methylenebis(5,5-dimethylcyclohexane-1,3-dione)(CAS DataBase Reference)
• NIST Chemistry Reference: 2,2'-Methylenebis(5,5-dimethylcyclohexane-1,3-dione)(2181-22-8)
• EPA Substance Registry System: 2,2'-Methylenebis(5,5-dimethylcyclohexane-1,3-dione)(2181-22-8)

Safety Data

• HazardClass: IRRITANT
• Hazardous Substances Data: 2181-22-8(Hazardous Substances Data)

Usage

General Description

2,2'-Methylenebis(5,5-dimethylcyclohexane-1,3-dione) is a chemical compound with the molecular formula C20H26O4. It is commonly known as MDH or methylene bisphenyl isocyanate and is used in the production of polyurethane foams and coatings. MDH is a highly reactive chemical that can cause skin and respiratory irritation, and is classified as a potential carcinogen. It is also known to cause allergic reactions in some individuals. Due to its potential health hazards, proper safety measures must be taken when handling and using MDH.

Upstream product

• 562-13-0 2,2-dimethyl-1,3-cyclohexanedione 
• 100-97-0 hexamethylenetetramine 
• 126-81-8 dimedone 
• 1192-37-6 methylenecyclohexane 
• 110-89-4 piperidine 
• 64-17-5 ethanol 
• 7732-18-5 water 
• 67-68-5 dimethyl sulfoxide 
• 100-34-5 benzene diazonium chloride 
• 73633-55-3 3,3',4,4',5,5'-hexamethyl-2,2'-dipyrrylmethane 
• 44826-45-1 3-sulfopropanoic acid 
• 142-96-1 dibutyl ether 
• 78666-54-3 N,N'-bis-(4-methoxy-phenyl)-methanediamine 
• 53654-69-6 N,N'-bis-(4-chloro-phenyl)-methanediyldiamine 

Downstream Products

• 27361-25-7 3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione 
• 309972-04-1 10-benzyl-3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione 
• 701-58-6 5,5-dimethyl-3-methylamino-2-cyclohexenone 
• 83231-63-4 10-(2-Hydroxy-phenyl)-3,3,6,6-tetramethyl-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione 
• 83231-60-1 3,3,6,6-tetramethyl-9-phenyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione 
• 83231-61-2 3,3,6,6-Tetramethyl-10-p-tolyl-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione 

Relevant articles and documents

Unusual course of the reaction of N-(tosylmethyl)thiourea and n-(azidomethyl)thiourea with sodium enolate of dimedone

The end product of the reaction of N-(tosylmethyl)thiourea or N-(azidomethyl)thiourea with sodium enolate of dimedone is bis(2-hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)methane (methylenebisdimedone) instead of the expected 8a-hydroxy-7,7-dimethyl-2-thiox

Thermal and microwave assisted synthesis of N-aroylamino acridinediones

A series of N-aroylamino acridinediones (3a-3d and 6a-6e) have been synthesized from tetraketones (1 and 4) and benzoic hydrazides (2a-2d and 5a-5e) under thermal and microwave irradiation conditions with solid supports.

Conversion of 10-bromo-10,11-dihydrocinchonidine into 8-oxa-1-azabicyclo[4. 3.0]nonane derivatives and related compounds: A structural study

The structure of dehydrobromination products of 10-bromo-10,11- dihydrocinchonidine 2c has been investigated in order to explore the scope of the conversions so far observed for quinine and cinchonine. The 2c rearranges into a mixture of 4(S)-(E-propenyl)-6(S),7(R)-(quinol-4-yl)-8-oxa-1(R)- azabicyclo[4.3.0]nonane 6 and its Z-propenyl diastereomer 8 in the ratio 3: 1 and also provides Z-3,10-didehydro-10,11-dihydrocinchonidine 18. The mixture of 6 and 8 undergoes catalytic hydrogenation giving 4(S)-propylo-6(S),7(R)-(quinol- 4-yl)-8-oxa-1(R)-azabicyclo[4.3.0]nonane 10. On treatment with an acid the alkaloid 6 yields [4(S)-E-propenyl-2(S)-piperidinyl]-4-quinoline α(R)-methanol 14. Its side chain undergoes hydrogenation affording 4(S)-propylo-derivative 12 which also forms on treatment of 10 by acid. The alkaloids 6, 8, 10, 12 and 14 appear as dominating conformers in their equilibrium mixtures.

Thiamin biosynthesis. II. A novel biosynthetic transformation of the S-methyl moiety of methionine.

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Merging supramolecular catalysis and aminocatalysis: Amino-appended β-cyclodextrins (ACDs) as efficient and recyclable supramolecular catalysts for the synthesis of tetraketones

Well-designed amino-appended β-cyclodextrins (ACDs) with an amino side chain of different lengths at the primary face of β-CD were synthesized and employed in the catalytic synthesis of a series of tetraketones as supramolecular catalysts in water for the first time. Yields of 58-97% were obtained with up to 30 examples of substrate. The catalyst could be recycled easily, while a 92% yield and 84% rate of catalyst recovery could be achieved after 8 cycles of catalyst recycling. Moreover, a catalytic mechanism merging supramolecular catalysis and aminocatalysis could be proposed through detailed 1D and 2D NMR, ESI-MS and Job plot analyses. This protocol retained the promising characteristics of ambient temperature, green medium, simple operation, broad substrate scope, excellent yields, superb catalyst recycling performance and unique catalytic mechanism.

A novel three-component reaction of anilines, formaldehyde and dimedone: simple synthesis of spirosubstituted piperidines

A three-component condensation of anilines with dimedone and formaldehyde leads to the formation of 3,5-dispirosubstituted piperidines. This simple reaction can serve as a convenient source of 3,5-disubstituted piperidines as well as polyfunctional 3-spir