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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 638352Generated: October 29, 2026

Bromine → 4-Methylphthalic anhydride

https://huagongshe.com/reaction/638352

Reaction equation

Participants

RoleNameHCIDCharge
ReactantBromineHCID 24408—
Reactant3a,4,7,7a-Tetrahydro-5-methyl-1,3-isobenzofurandioneHCID 98496—
ReactantSulfurHCID 5362487—
SolventAcetic AcidHCID 176—
Product4-Methylphthalic anhydrideHCID 8806916%

Reaction Steps

Various processes are known for preparing substituted phthalic anhydrides. In two such processes 4-methyl-1,2,3,6-tetrahydrophthalic anhydride is dehydrogenated either by sulfur or by bromine in acetic acid. Yields of 4-methylphthalic anhydride of 59 percent to 87 percent are claimed for the former method, while the latter gives only a 16 percent yield [see Izv. Akad. Nauk. SSSR, Ser. Khim., 6, 1315 (1973) English translation, page 1271 and D. Craig, Journal of American Chemical Society, Vol. 72, page 3732, (1950)].

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS04560772
Source datasetuspto-grants-1985_12
ORD IDord-d9cfeedfd8554c4fbfa1db5aac0bd013
Source noteuspto-grants-1985_12