2-Halomethyl derivatives of 3-functionalized 5-tert-butylfurans are phosphorylated under conditions of the Michaelis-Becker and Arbuzov reactions similarly to other halomethylfurans. No effect of the tert-butyl substituent on the yield of the reaction products was found in this case. Contrary to that, the 2-methoxymethyl derivative of 3-chloromethyl-5-tert-butylfuran proved to be more thermostable than its analog containing no tert-butyl substituent. As a result, the yield of phosphonate in the Michaelis-Becker reaction under similar conditions increases 2.5 times. The observed stabilization of the furan ring is explained by shielding of its oxygen atom by the tert-butyl group.
2-Halomethyl derivatives of 3-functionalized 5-tert-butylfurans are phosphorylated under conditions of the Michaelis-Becker and Arbuzov reactions similarly to other halomethylfurans. No effect of the tert-butyl substituent on the yield of the reaction products was found in this case. Contrary to that, the 2-methoxymethyl derivative of 3-chloromethyl-5-tert-butylfuran proved to be more thermostable than its analog containing no tert-butyl substituent. As a result, the yield of phosphonate in the Michaelis-Becker reaction under similar conditions increases 2.5 times. The observed stabilization of the furan ring is explained by shielding of its oxygen atom by the tert-butyl group.
The present invention provides a heterocyclic compound represented by the following formula (I), which has a glucagon antagonistic action and is useful for the prophylaxis or treatment of diabetes and the like, a compound represented by
wherein ring A is an optionally substituted benzene ring and the like; Y is a nitrogen atom and the like; X is —O— and the like; R
4
is a hydrogen atom and the like; R
5
and R
6
are each independently a hydrogen atom and the like; R
1
is an optionally substituted hydrocarbon group and the like; R
2
is a hydrogen atom and the like; and R
3
is —(CH
2
)
3
—COOH and the like, or a salt thereof.