Patent ID: 7407691

Claim:
A compound of a formula (1): wherein R 1 represents a hydrogen atom or an alkyl group having from 1 to 5 carbon atoms; R 2 represents a hydrogen atom, —NCO, —NCS, —OCHF 2 , —CH 2 F, —OCF 2 CF 2 H, —OCF 2 CHFCF 3 , or —Y 1 —(CF 2 )s-CF 3 , in which Y 1 represents —O—, —S—, —COO—, —OCO—, —CO—, —CH═CH—, or —C≡C—, s indicates an integer of from 0 to 10; A 1 represents a 1,4-phenylene group, or a 1,4-phenylene group in which any hydrogen atom is substituted with a halogen atom, a cyano group, a methyl group, an ethyl group, a methoxy group, a hydroxy group, a formyl group, an acetoxy group, an acetyl group, a carbonylmethyl group, a carbonyltrifluoromethyl group, a difluoromethyl group, or a trifluoromethyl group; A 2 and A 3 each independently represent a 1,4-cyclohexylene group, a 1,4-phenylene group, a pyridine-2,5-diyl group, a pyridazine-3,6-diyl group, a pyrimidine-2,5-diyl group, a naphthalene-2,6-diyl group, a tetrahydronaphthalene-2,6-diyl group, a 1,4-cyclohexylene group in which any hydrogen atom is substituted with a fluorine atom, or a 1,4-phenylene group in which any hydrogen atom is substituted with a halogen atom, a cyano group, a methyl group, an ethyl group, a methoxy group, a hydroxy group, a formyl group, an acetoxy group, an acetyl group, a carbonylmethyl group, a carbonyltrifluoromethyl group, a difluoromethyl group or a trifluoromethyl group; X 1 represents a single bond, —O— or —OCO—; X 2 and X 3 each independently represent a single bond, —CH═CH—COO—, —OOC—CH═CH—, —CH 2 CH 2 —COO—, —OOC—CH 2 CH 2 —, —COO—, —OCO—, —OCH 2 —, —CH 2 O—, —OCF 2 —, —CF 2 O—, —CH 2 CH 2 —, —C≡C—, —NHCO—, or —CONH—; m indicates an integer of from 0 to 20; and n indicates 1 or 0.