Compound, resin, composition, resist pattern formation method, circuit pattern formation method, and purification method

A compound comprising a condensed skeleton of an aromatic compound represented by formula (1-1) and an aromatic aldehyde represented by formula (2-1):

• wherein
• A represents an aromatic ring;
• R is each independently an alkyl group having 1 to 30 carbon atoms and optionally having a substituent, an aryl group having 6 to 30 carbon atoms and optionally having a substituent, an alkenyl group having 2 to 30 carbon atoms and optionally having a substituent, an alkynyl group having 2 to 30 carbon atoms and optionally having a substituent, an alkoxy group having 1 to 30 carbon atoms and optionally having a substituent, a halogen atom, a nitro group, an amino group, a carboxylic acid group, a crosslinkable group, a dissociation group, or a thiol group;
• the alkyl group, the aryl group, the alkenyl group, the alkynyl group, and the alkoxy group each optionally contain an ether bond, a ketone bond, or an ester bond;
• k is an integer of 0 or more;
• and
• L is an integer of 1 or more, and
• wherein
• B represents an aromatic ring;
• R is each independently an alkyl group having 1 to 30 carbon atoms and optionally having a substituent, an aryl group having 6 to 30 carbon atoms and optionally having a substituent, an alkenyl group having 2 to 30 carbon atoms and optionally having a substituent, an alkynyl group having 2 to 30 carbon atoms and optionally having a substituent, an alkoxy group having 1 to 30 carbon atoms and optionally having a substituent, a halogen atom, a nitro group, an amino group, a carboxylic acid group, a crosslinkable group, a dissociation group, or a thiol group;
• the alkyl group, the aryl group, the alkenyl group, the alkynyl group, and the alkoxy group each optionally contain an ether bond, a ketone bond, or an ester bond;
• p is an integer of 0 or more;
• and
• q is an integer of 1 or more,
• provided that at least one hydroxy group is bonded to a carbon atom adjacent to a carbon atom to which a formyl group is bonded.