Sharma, M. L. et al. published their research in Journal of the Indian Chemical Society in 1991 | CAS: 1877-75-4

2-(4-Methoxyphenoxy)acetic acid (cas: 1877-75-4) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. But ether is more polar than alkenes. Ethers feature bent C–O–C linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp3.Synthetic Route of C9H10O4

Synthesis and plant growth retardant activity of trialkylammonium iodides containing an aromatic ether moiety was written by Sharma, M. L.;Rani, Geeta;Talwar, K. K.;Kalsi, P. S.. And the article was included in Journal of the Indian Chemical Society in 1991.Synthetic Route of C9H10O4 This article mentions the following:

Alkyldimethyl(2-phenoxyethyl)ammonium iodides 4-R1C6H4OCHR2CH2NR3Me2I (I; R1 = H, MeO; R2 = H, Me; R3 = Me, Et) were prepared from phenoxyacetic acid derivatives by chlorination and amidation to give amides, subsequent reduction of the latter and quaternization. I were effective as growth inhibitors for Brassica rapa. In the experiment, the researchers used many compounds, for example, 2-(4-Methoxyphenoxy)acetic acid (cas: 1877-75-4Synthetic Route of C9H10O4).

2-(4-Methoxyphenoxy)acetic acid (cas: 1877-75-4) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. But ether is more polar than alkenes. Ethers feature bent C–O–C linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp3.Synthetic Route of C9H10O4

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem