Methallylation

With higher alkenes, three kinds of products, namely alkenyl acetates, allylic acetates and dioxygenated products are obtained[142]. The reaction of propylene gives two propenyl acetates (119 and 120) and allyl acetate (121) by the nucleophilic substitution and allylic oxidation. The chemoselective formation of allyl acetate takes place by the gas-phase reaction with the supported Pd(II) and Cu(II) catalyst. Allyl acetate (121) is produced commercially by this method[143]. Methallyl acetate (122) and 2-methylene-1,3-diacetoxypropane (123) are obtained in good yields by the gas-phase oxidation of isobutylene with the supported Pd catalyst[144]. 

When allylic alcohols are used as an alkene component in the reaction with aryl halides, elimination of /3-hydrogen takes place from the oxygen-bearing carbon, and aldehydes or ketones are obtained, rather than y-arylated allylic alcohoIs[87,88]. The reaction of allyl alcohol with bromobenzene affords dihydrocinnamaldehyde. The reaction of methallyl alcohol (96) with aryl halides is a good synthetic method for dihydro-2-methylcinnamaldehyde (97). 

ANALGESICS, ANTIPYRETICS, AND ANTIINFLAT TATORYAGENTS] (Vol 2) Methallyl angelate [61692-78-2]... 

This method of preparation is suitable for producing primary alkyl lactates but is unsatisfactory for /3-methallyl lactate because the strong mineral acid catalyzes the rearrangement of methallyl alcohol to isobutyraldehyde. Methyl lactate can be made conveniently (80-85% yield) by heating 1 mole of lactic acid condensation polymer with 2.5-5 moles of methanol and a small quantity of sulfuric acid at 100 for 1-4 hours in a heavy-walled bottle, such as is used for catalytic hydrogenation with a platinum catalyst. 

The checkers obtained a heavy slurry at this stage which became heavier during addition of methallyl chloride. They found it necessary to dilute with more tetrahydrofuran (about 450 ml. for the scale given in the procedure) before methallyl chloride was added. 

Chloro-2-methylpropene (methallyl chloride) is available from Fluka A G and Eastman Organic Chemicals. The chloride, b.p. 72° (760 mm.), was distilled before use. 

To minimize the gradual embrittlement that can occur on aging of cyanoacrylate adhesives, plasticizers are added. Some of the materials, which have been used as plasticizers, include phthalates, phosphonates, acyl esters, succinates, and cyano-acetates. The use of allyl, methallyl, and crotyl phthalates is also claimed to improve thermal resistance properties in addition to plasticizing the adhesive [23]. 

Chemical Designations - Synonyms gamma-Chloroisobutylene 3-Chloro-2-methylpropene beta-Methallyl chloride beta-Methylallyl chloride Chemical Formula CH2=C(CH3)CH2C1. 

Ti(0-/-Pr)4, i-BuMgCl, THF, rt, 69-97% yield. Methallyl and other substituted allyl ethers are not cleaved, but ester groups are partially removed, as expected. ... 

Pd(Ph3P)4, RS02Na, CH2CI2 or THF/MeOH, 70-99% yield. These conditions were shown to be superior to the use of sodium 2-ethylhexanoate. Methallyl, crotyl, and cinnamyl ethers, the Alloc group, and allylamines are all efficiently cleaved by this method. ... 

Cleavage of the methallyl ester is achieved in 80-95% yield by solvolysis in refluxing 90% formic acid. Cinnamyl and crotyl alcohols are similarly cleaved. ... 

This syrup is treated with sufficient 20% sodium hydroxide solution to raise the pH to 10. A violent reaction occurs. The reaction mixture is diluted with 50 partsof water, stirred, coo led and filtered. The material collected on the filter is recrystallized from 10% ethanol to yield a mixture of 1 -methallyl-3.ethyl. emino-1,2,3,4-tetrahydro-2,4 3yrimidinedione and 1. ethyl-3-methallyl-6-emino-1,2,3,4-tetrahydro-2,4 3yrimidinedione melting at about 157°-159°C. 

In a 1-1. round-bottomed flask equipped with a condenser are placed 78.0 g. (0.56 mole) of commercial anhydrous potassium arbonate, 45.0 g. (0.50 mole) of methallyl chloride (Note 1), 55.0 g. (0.55 mole) of 2,4-pentanedione (Note 1), and 300 ml. of anhydrous ethanol (Note 2). The mixture is refluxed on a steam bath for 16 hours. The condenser is replaced by a distilling head and condenser, and about 200 ml. of ethanol is distilled from the mixture (Note 3). Ice water (600 ml.) is added to dissolve the salts, and the mixture is extracted three times with ether. The... 

Eastman Organic Chemicals practical grade methallyl chloride was distilled (b.p. 70-71°) Union Carbide Chemicals Co. 2,4-pentanedione was distilled (b.p. 134.5-135.5°). 

In the distillation residue (5.7-6.3 g.) remain other byproducts, presumably l,l-dimethallyl-2-propanone, 3-methallyl-2,4-pentanedione, and 3,3-dimethallyl-2,4-pentanedione (indicated by vapor phase chromatography). The checkers carried out v.p.c. analyses using an 8-ft. column of 5% silicone oil XE-60 on Diatoport S at 100° for analysis of the distillate and 175° for analysis of the residue. 

Methyl-5-hexen-2-one has been prepared by alkylation of acetoacetic ester with methallyl chloride, followed by cleavage the overall yield in the two steps was 51%.2... 

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